Flentrop open house for new UK organ

Michael McNeil

Michael McNeil has designed, constructed, voiced, and researched pipe organs since 1973. Stimulating work as a research engineer in magnetic recording paid the bills. He is working on his Opus 5, which explores how an understanding of the human sensitivity to the changes in sound can be used to increase emotional impact. Opus 5 includes double expression, a controllable wind dynamic, chorus phase shifting, and meantone. Stay tuned.

Editor’s note: The Diapason offers here a feature at our digital edition—four sound clips. Any subscriber can access this by logging into our website (thediapason.com), click on Magazine, then this issue, View Digital Edition, scroll to this page, and click on each <soundclip> in the text.

Many American organists have traveled to Europe and heard the sounds of older organs that make Bach a revelation. American organ building was for much of its history rooted in the Anglican tradition and the Romantic sounds of organbuilders like Ernest M. Skinner, and neither of those great art forms are an ideal medium for Bach. Tentative steps in the Anglican tradition were made as early as the 1930s to recreate this European sound, but they did not amount to a revelation. The revelation occurred with a British-born virtuoso, E. Power Biggs, who brought a sound to America that would convincingly play Bach in the form of an organ built by D. A. Flentrop. Biggs paid for this organ out of his own pocket and in 1958 found a home for it in the very reverberant acoustics of what was known at the time as the Busch Reisinger Museum.¹ His recordings of this Flentrop energized the budding Organ Reform Movement in the United States and inspired many American organbuilders. Listen to the end of the Fugue in A Minor, BWV 543ii <Soundclip 1>.

Dirk Andries Flentrop (1910–2003) worked in his father’s organbuilding shop and with Theodor Frobenius in Denmark, eventually taking over his father’s business. He was intensely interested in classical organ design, and he gave a lecture at a very young age in 1927 in which he promoted the use of mechanical action and slider windchests.² A conversation with Flentrop in the 1970s turned to his earlier career, and he recalled that he was traveling on a streetcar in Rotterdam when bombs started falling on that city in World War II. Everyone on the streetcar agreed there was no point in getting off, and they continued traveling to their destinations as bombs fell. The date was May 10, 1940, the year he took over his father’s business. I sailed with my parents on the SS Rotterdam in 1964 and still remember the shock of seeing upturned docks as we approached the harbor at Rotterdam and whole city blocks of uncleared rubble decades after the bombing.

Flentrop’s sound

The sound of pipe organs can be described subjectively and objectively. Subjectively, the sound of D. A. Flentrop is bright and “instrumental,” where individual pipes in the principal chorus have rich harmonic content. This is very different from what is today called vocale voicing, which emphasizes less harmonic power. Flentrop’s richly harmonic sound creates a scintillating principal chorus with clarity of pitch.

A key component of this sound, and a strong departure from the Romantic and Anglican traditions, is the expression of “chiff.” E. Power Biggs described chiff as the articulate “ictus” of a sound, adding clarity to rhythm and contrapuntal harmony. Chiff is not just percussive noise. It consists of higher natural harmonics to which the human ear is very sensitive, quickly defining the pitch. Flentrop was a master of this percussive speech, and it was always musical and fast. Chiff can be modulated with a sensitive mechanical action and low wind pressures (i.e., with little or no key pluck). Biggs was adept at this on his Flentrop, easing the pallets open for a smooth treble line while crisply opening the pallets to delineate inner voices with more chiff.

Later expressions of this articulation in what became known as neo-Baroque voicing are often heard as a slow, gulping sound. You never hear slow, gulping speech in a Flentrop organ, and as the data will show, Flentrop’s voicing exhibits no relationship to neo-Baroque voicing recipes.³

There is ample evidence that much of D. A. Flentrop’s sound is based on examination of the work of Arp Schnitger, and Schnitger’s sound is much more instrumental in character than modern vocale voicing. The similarity to Schnitger extends also to the design of the reeds, whose basses are the source of a smooth and powerful fundamental.

Flentrop organs have considerable presence, due in large part to the shallowness of the casework found in all of his organs. Flentrop related that the maximum depth of a case should be no deeper than the reach of an arm from the back doors of the case to its façade pipes. Deep cases and chambers will tend to absorb sound, especially the higher harmonics that create the sense of presence. I find it interesting that unaltered manual divisions of Cavaillé-Coll organs, while using higher pressures with Romantic scaling and voicing, almost never exceeded twelve stops and always used slider chests with mechanical action, reflecting some of the important design features of Flentrop organs.

The generosity of D. A. Flentrop

D. A. Flentrop was secure in his knowledge and very willing to share it. I was the recipient of his generosity on several occasions when he toured the United States with his senior voicer, Sijmen “Siem” Doot, to maintain and tune his organs. Doot, born in 1924, entered Flentrop’s service in 1939 and retired in 1988. Ed Lustig at Flentrop Orgelbouw confirmed that Franz Rietsch, Rob Oudejans, Johannes Steketee, and Doot assembled the Flentrop organ in Saint Mark’s Episcopal Cathedral, Seattle, Washington, in 1965, while Steketee and Doot remained to voice the organ. The voicing data in this article is a testament to their skill. I was introduced to Flentrop by Albert Campbell in 1971. After scouring the literature and finding mostly subjective opinions with very little data, I quickly discovered that Flentrop was genuinely interested in answering the detailed questions of a budding organbuilder. When I asked him if he would grant me permission to take measurements of his organs, he replied, “imitation is the finest form of flattery. Your ears will be different than mine, and you will use your observations to find your own sound.” He was right, but it took quite some time before I began to understand some of those observations, and the data continues to generate insights.

I again met Flentrop in the Campbell home after completion of my Opus 1, and by that time I had learned enough to ask deeper questions. Flentrop had nearly completed the tuning of his organ at the University of California, Santa Barbara, and in a further gesture of generosity, Flentrop said, “If you finish the cone tuning of the Hoofdwerk Mixtuur, we can answer your questions.” I agreed to finish the tuning work on the Flentrop organ, and both he and Mr. Doot spent the whole day answering my questions.

Flentrop slider windchests

D. A. Flentrop organs have exclusively featured mechanical key action and slider windchests since 1949. Stop actions were mechanical, as well, and only in his larger organs do we find electric slider motors and combination actions. Organbuilders who looked to the literature for the design principles of slider chests in the 1970s often found the effort frustrating. Flentrop willingly shared a great deal of his design practice. In Figure 1 we see a drawing made by the author from notes of a conversation with Flentrop regarding channel design. Flentrop recommended that the cross-sectional area of the key channel should have about 20–30% more area than the combined areas of all of the pipe toes it would need to wind. A small vent hole at the end of the channel served two functions—to prevent ciphering and to dampen resonances in the channel that would interfere with reeds. Reeds that are equal in length to the channel that feeds wind to them may get much louder, and those not quite equal to that length may get much weaker and more dull in timbre from channel resonance. I noted that the bottom of the key channels in the Flentrop organ at the University of California, Santa Barbara, were covered in a thick paper that had pin pricks in a few channels in various positions, likely done to reduce channel resonance.

Flentrop stated that pallets did not need to exceed 200 millimeters (about eight inches) in length, but I have found much longer pallets in Hook organs. I did not ask how to trade off key channel widths and heights for a given area, nor the flow areas of the pallets, and these tradeoffs can be complex. Suffice it to say that the flow area of a pallet is the length of its opening times the distance the pallet is pulled open by the key (an open pallet has a triangle of flow at each side, and when combined, these triangles make a rectangle). It is also interesting to note that a pallet will not flow significantly more wind to a channel when its pull is more than half of the channel width (think about the height of those triangles that flow wind relative to the width of the channel). For a given pallet pull and a key channel width that is twice the pull, only a longer pallet will flow more wind to the channel.

The 1863 Hook organ at the former Church of the Immaculate Conception in Boston, Massachusetts, has roughly 460-millimeters-long pallets feeding 406-millimeters-long flue and reed channel openings in the Great bass octave (there are two pallets per note). The Romantic voicing of the Hook organ requires a very large volume of wind to feed its very deep flueways and very widely opened toes, which are much larger than Flentrop’s. At Saint Mark’s, Flentrop likewise used two pallets for the six bass notes of the Hoofdwerk, with pallet opening lengths of 155 millimeters, flue and reed channel widths of 21 millimeters and 17 millimeters, respectively, and a channel height of 79 millimeters. Readers who are interested in comparing the differences in the voicing of Flentrop and Hook organs can find the Hook data in The Diapason.⁴

Flentrop’s patented slider

Slider windchests in ancient organs often suffered from the advent of central heating. Topboard bearers are shimmed with layers of paper for a close fit between the slider, the windchest table on which it rests, and the topboard above it. With central heating and the resulting low humidity, shrinking wood caused these sliders to leak wind and impair the tuning. Many different forms of slider seals were invented in the twentieth century, most of which worked quite well. Flentrop’s system is patented and rather complex, but it is extremely reliable. Flentrop used two sliders, separated by springs with a leather-faced conduit for the wind between the two sliders. Figure 2 (see page 15) shows this slider seal mechanism in relation to the pallets, key channels, and topboards.

An objective approach to Flentrop’s sound

If you want to discover how to achieve a certain sound, it is often educational to closely observe the organs you like and those you do not. The objective differences will teach you what matters. Readers who want some perspective on the following Flentrop data will find a description of the voicing of several historic organs in The Diapason.⁵

The absolute minimum data needed to understand the sound of an organ is:

• pipe diameters (inside);

• mouth widths;

• toe diameters;

• mouth heights (also known as “cutups”)

• flueway depths.

Complete descriptions of these parameters can be found in the article mentioned above.⁶ In a nutshell, larger pipe diameters, wider mouth widths, larger toe diameters, and deeper flueways yield more power. Mouth heights control timbre, and higher mouths reduce harmonic power and brightness. Flutes typically have much higher mouths than more harmonically rich principals.

Wider scales produce an “ah” timbre, and narrower scales will progress towards an “ee” timbre, emphasizing higher harmonics. Flentrop stated that he used a constant scale of pipe diameters and mouth widths for the principal chorus in most environments and acoustics, which meant that he wanted a specific vowel timbre for all of the pipes at the same pitch and a specific power balance across the range of frequencies from bass to treble.

For different acoustics Flentrop used different pressures and voicing, adjusting the toe diameters and cutups. Ascending trebles were achieved in the toe diameters. Figure 3 shows Flentrop’s chorus scaling written in his own hand in 1971 with numerical values he had memorized.

Flentrop reeds were often made by the firm of Giesecke to Flentrop’s specifications. A description of the data needed to understand the sound of a reed can be found in an article in The Diapason.⁷ The author’s measurements of the Saint Mark’s reeds were not taken in sufficient detail to merit showing them. Flentrop reed designs are very similar to Schnitger’s and use tin-lead plates with restricted openings soldered to wide, lightly tapered, and deeply cut shallots for powerful, smooth basses. These typically transition to open, parallel shallots without plates in the tenor.

Taking the data at Saint Mark’s

I have been fortunate that many of those who are a gate to the access to some important organs have granted me permission to measure them. In 1972 that good fortune allowed me to take measurements of Flentrop’s organ at Saint Mark’s Episcopal Cathedral, Seattle, Washington, the organ Flentrop considered his largest by virtue of its 32′ façade pipes. The stoplist of the Saint Mark’s organ is easily found on the internet.⁸

The cathedral measures an estimated 150 feet in length and width, with a flat, wooden ceiling about 90 feet high. The walls are very thick concrete, yielding an acoustical reverberation of about five plainly audible seconds in the soprano range.⁹ The reverberation drops dramatically in the tenor and bass as a consequence of the very large windows, through which the lower frequencies easily pass.

Richard Frickmann, a life-long friend, and I drove over a thousand miles to visit this organ, and upon arrival in the early morning we sat in the pews in the empty cathedral, looking back at the organ. Glenn White, who maintained the organ, noticed our interest in this magnificent Flentrop and struck up a conversation. Learning that we were eager to find scaling data of the pipes, he questioned us for about five minutes and admitted that no one had taken the time to measure the pipework. He took us to the office and gave us the keys to the Flentrop casework, the organ loft, and the cathedral, asking that we return them when we were done. This was a stunning opportunity and one rarely offered. Mr. Frickmann and I took over fifty pages of data, interspersed with trips to the local twenty-four-hour pancake house to refuel with food and coffee. I had brought with me copies of scaling sheets and measuring tools, and Mr. Frickmann wrote down the numbers as I called them out from the walkways behind the windchests. After about twenty-four continuous hours of work, we handed in the keys to the office.

A word of caution on the data is in order. I took this data in 1972, very early in my career. I had experience with Flentrop’s organ at the University of California at Santa Barbara, and I understood basic scaling and data collection. But what I did not yet appreciate at the time was the importance of measuring the depth of the flueway. My general observations of the flueways of the Saint Mark’s organ were that “they tend to be consistent throughout the organ relative to pitch, much wider than current neo-Baroque work, but narrower than the voicing of the early American builders like Johnson and the Hooks.” Later measurements of Flentrop flueways provided a generalized model of the flueways for the Saint Mark’s organ. Please be aware that these are probably in the ballpark, but they are assumptions.

I was very careful in the handling of the pipes and making sure that their mouths faced in their original directions (this affects tuning on larger pipes whose mouths can be close to other pipes and shaded by them, lowering their pitch). The measurements of these pipes will have some inaccuracy from the time constraints. For larger pipes the measurements are likely better than +/- 1 millimeter, and for the very smallest pipes, about +/- 0.2 millimeter. The data is presented in halftone deviations from Normal Scale to make the relationships clear, as tables of numbers do not easily convey their meaning. These Normal Scales were published in the author’s article, “1863 E. & G. G. Hook Opus 322: Church of the Immaculate Conception, Boston, Massachusetts,” Part 1.¹⁰ Those who want actual measurements can use those tables to convert the Normal Scale data into dimensions, or they can email the author for a copy of the Excel spreadsheet with the more accurate raw dimensional data.¹¹

The Hoofdwerk

Larger pipe diameters generate more power, and smaller diameters generate a brighter timbre. Flentrop’s principal chorus scales combine these factors into the sound he wanted. His scaling model in Figure 3 is seen as a dashed blue line in Figure 4. The model generally follows the Saint Mark’s data. As Flentrop noted, the mixtures are narrower. Flutes trend much wider as the pitch ascends.

Sound clips of the Saint Mark’s Flentrop in the digital edition of this article allow one to hear these power and timbre balances. They were derived from 1981 recordings of James Welch, organist, another life-long friend. The recording engineer, Dave Wilson, was known as one of the world’s best, and he recorded Welch on Flentrop organs. I was present in 1981 for the Saint Mark’s recordings, mostly to help with touching up the tuning of the reeds. I also made suggestions for stop registrations that ran counter to the prevailing wisdom of the time, dictating a minimal use of foundations to aid in clarity of pitch. This was not necessary on a Flentrop, whose foundations can be combined to any degree and still maintain clarity of pitch. Amassing foundations, as any Romantic organist knows well, is a source of rich chorus depth, and it is heard to great effect in Charles-Marie Widor’s “Andante cantabile” from Symphonie IV in <Soundclip 2>.

We made many experiments with microphone placement. The proper power balances of the different Flentrop divisions were finally achieved by placing microphones on very tall stands about twenty to thirty feet in front of the Rugwerk, the division that has the most presence for the congregation. Having been accustomed to the practice of using fast tempos in dry acoustics, Welch and I discussed appropriate tempos for the reverberant acoustic of Saint Mark’s. Borrowing headphones from the recording engineer to hear what the sound was like in the room at the microphones, he arrived at the tempo we hear in C. P. E. Bach’s Toccata and Fugue in D Minor, which takes full advantage of Saint Mark’s long reverberation <Soundclip 3>.

Late in the all-night recording session a note went dead in the Rugwerk. The organ had been in service for only sixteen years at this time, and a failure was unexpected. I pulled up the floor panels in the choir loft, which gave access to the Rugwerk trackers, and the culprit was a torn piece of weak leather that connected a long horizontal tracker at a suspension point. None of the other connectors showed the slightest sign of wear. I made a temporary fix, adjusted the action, and we continued recording well into the next morning.

Figure 5 shows the scales of the mouth widths, and these generally imitate the diameter scales. Normal Scale mouth widths are based on 1⁄4 of the circumferences of Normal Scale diameters, and as Flentrop almost exclusively used 1⁄4 mouths, we would expect a similarity to the diameter scales. Some of these mouth widths appear to be a bit wider than 1⁄4 of the circumference, and this may indicate that the pipes were slightly tapered, something I did not measure, and which is not uncommon. Inside diameters were measured at the top of the pipes. If the pipes have a slight taper, the true diameter scales at the bottom will be larger and will more closely match the Flentrop model in Figure 4, as well as the mouth scales in Figure 5.

Figure 6 shows mouth heights, or what is more commonly known as “cutups.” The cutup controls timbre. A higher mouth will reduce the harmonic content, and smooth flutes have higher cutups. These can be clearly seen in the lofty cutups of the 8′ Roerfluit. Normal Scale mouth heights are calculated as 1⁄4 of the Normal Scale Mouth Width, a common recipe in neo-Baroque voicing. In Figure 6 we see that Flentrop did not use this recipe. The Saint Mark’s cutups are much higher, and they have no relationship to the mouth width scales. They are also highly variable as a free voicing parameter. Flentrop raised the cutup until the desired timbre was achieved and the speech was fast. This is why you do not hear slow, gulping speech in a Flentrop organ.

The soaring cutups of the Roerfluit

The soaring cutups of the 8′ Roerfluit illustrate how Flentrop achieved a rich harmonic timbre in his principal chorus and a smoother, warmer timbre in the flutes. While Flentrop is noted for a brighter, “instrumental” timbre, which strongly implies lower cutups, Figure 6 clearly shows that his cutups were much higher than the neo-Baroque recipe. As an example, the cutup of the 8′ Roerfluit tenor C pipe in Figure 6 is +5 halftones, while its mouth width in Figure 5 is -5 halftones, revealing a cutup that is a stunning 10 halftones higher than the neo-Baroque recipe.

Figure 7 (see page 18) shows the relative flow of wind in the pipe toes. Larger pipe toes will flow more wind and yield more power. Received wisdom relates that Flentrop used “open toe” voicing, but Flentrop toes are in most cases quite restricted. Much more open toes can be found in Hook organs. Hook toe diameters also have high variability at a specific pitch, very unlike the more regular wind flow patterns we see with D. A. Flentrop and Gottfried Silbermann.¹³

The values in Figure 7 are toe constants, a number that represents relative flow. Flentrop suggested to me that a reasonable starting point for a toe diameter is the square root of its resonator diameter. The area of that closed toe represents a constant of “1,” and as you can see in Figure 7, Flentrop converged on that number at about 1′ pitch and increased the flow in both deeper and higher pitches. The area of the toe is proportional to the toe constant, i.e., a toe constant of “2” has twice the area of a toe with a constant of “1.” One added feature is that the toe constant compensates for mouths that are wider or narrower than the Normal Scale mouth of 1⁄4 of the circumference. For Flentrop this does not matter, because he used 1⁄4 mouths, but for a builder like Gottfried Silbermann who used 2⁄7 mouths, or Ernest M. Skinner who used 1⁄5 mouths, this compensation is critical, because wider mouths need more wind and narrower mouths need less. The toe constant allows us to compare the relative flow of wind in pipes with different diameters and different mouth widths. A good example in Figure 7 is the 8′ Roerfluit, which has slightly more wind than the 8′ Octaaf. Although it has a much smoother timbre, the 8′ Roerfluit’s slightly more powerful fundamental adds chorus depth to the much brighter 8′ Octaaf.

Toes control power, and in Flentrop organs designed for smaller acoustics I have found toe constants of 0.6 in the lowest mixture pitches, and this is a very restricted toe. A fully open toe has a toe constant of about 4, which we see in the highest pitches of the 2′ Octaaf and III Scherp in Figure 7.

Note the consistency of wind flow in the Flentrop principal chorus pipes at a given pitch, with a minimum flow of wind at about 1′ in pitch and much more flow in the bass and treble. This represents a voicing model for the Saint Mark’s acoustic. Similar patterns of wind flow exist in the 1692 Schnitger organ in the Hamburg Jacobikirche.¹⁴

The wind flow of the 4′ Speelfluit in Figure 7 is very instructive. Its lower cutups, relative to the 8′ Roerfluit, are explained by its more restricted toes. Closing the toe has the tonal effect of raising the cutup for a much warmer timbre at a lower power. The Speelfluit adds color to the more powerful Roerfluit, while restraining the power of the combined flutes as accompanimental stops.

Figure 8 data are estimated flueway depths based on observation of other work by Flentrop. In 1972 I did not have tapered wedges for measuring flueway depths. Wooden wedges are the safest material for documentation, but for a voicer, brass or steel wedges will last longer.¹⁵ The important feature of Flentrop flueways is that they are not used as a primary means of controlling power. Flentrop flueways do vary, but they vary within a restricted range at a given pitch. Neo-Baroque voicing emphasized a cutup recipe set to 1⁄4 of the mouth width with “open toes.” The result was that a voicer was often forced to use very narrow flueways to regulate both power and timbre, and the resulting sound was typically thin in fundamental warmth with a slow, gulping speech on the verge of overblowing. Flentrop used wind pressures and toes to control power, not the flueways, and he adjusted the cutup to achieve the desired timbres with fast speech.

In both modern and ancient work we will find an enormous variation in flueway depths. Although it is very rarely measured, flueway depth is of critical importance in understanding the different sounds of pipe organs. As the flueway deepens, more breathiness is heard in the sound. This is corrected by an increasing amount and boldness of nicking as the flueway depth increases. This is one of the reasons you will find many bold nicks in deep Romantic flueways. Flentrop’s voicing finds the flueway depth that will yield a tolerable breathiness with a minimum degree of nicking, and this is the optimum point for chiff. This is not a deep flueway, but it is much deeper than the razor-thin neo-Baroque flueways that resulted from arbitrarily low cutups. Both Andreas and Gottfried Silbermann used much deeper flueways than Flentrop, and their milder chiff is the result of their bolder nicking. Readers can find the flueway depths for some important historical styles in The Diapason.¹⁶

Figure 9 shows what happens when we divide the area of the pipe toe (the radius of the toe, squared, times π) by the area of the flueway it feeds (the flueway depth times the mouth width). In Figure 9 we see this data as a ratio of those areas. This tells us a great deal about the speech onset of the pipes. If the pipe toe is closed to the point where its area is less than the flueway area, the pressure will drop in both the foot and the flueway.¹⁷ We often see this in organs with higher wind pressures where the toes are strongly reduced to control power. In this situation, however, not only does the pressure drop at the flueway, the buildup of pressure in the foot is slower, and this can lead to slower speech. This form of slower speech is not immediately obvious, but a chorus with ratios above 1.0 will have a prompt attack, while pipes with ratios of 0.5 will have a noticeably slower attack, as is often heard in the smooth solo voice of the classical French cornet.¹⁸ When we look at theatre organs with extremely high wind pressures and deep Romantic flueways, we also find extremely small toes that produce ratios well below 0.5. This is why the attack of theatre organ flue pipes is much slower than what we hear in a Flentrop.

Ultra-low area ratios also explain in part why theatre organ pipes never have chiff. A fast rise in pressure in the foot and flueway is essential to the production of chiff, and we hear this when Biggs crisply opens the pallets on his 1958 Flentrop. Ratios close to 1 or above will be conducive to a fast pressure rise and the production of chiff, and in Figure 9 we can see that no Flentrop pipes have values below 1, and most pipes have values well above 1. This is a feature of Flentrop voicing in all of his organs for which I have data, and it is a significant factor in Flentrop’s fast, articulate voicing. Flentrop flueways are not deep in the Romantic style, and their areas are relatively small, with the result that even Flentrop’s more restricted toes still supply much more wind than the flueways need, and the fast pressure rise produces chiff.

Chiff can be eliminated in any ratio of toe and flueway areas by simply applying many bold nicks, but Flentrop used nicking sparingly, and when it is used, it is typically very fine in nature. Hook voicing also features relatively high area ratios, but the voicers used many bold nicks on every pipe, and no chiff is audible in their voicing. Theatre organs combine ultra-low area ratios with very bold nicking and unsurprisingly never exhibit chiff.

Figure 10 shows the mouth of a Flentrop pipe from about 1980, which is articulate, even with its two bolder nicks. The finest nicking in the center of the languid is more typical of the Saint Mark’s organ. Note that the flueway, while not deeply open in the Romantic style, is much deeper than typical neo- Baroque voicing.

The Pedaal

Figure 11 shows the diameter scales of the Pedaal. The scales of the larger pipes are consistent with the Flentrop model in Figure 3, and the diameters of the larger pipes were measured at the bottom. The Mixtuur is also consistent with the model notes. Like the Hoofdwerk, the flutes trend much wider as the pitch ascends.

The wind pressure of the Hoofdwerk is 80 millimeters, which is interestingly the same pressure found in the restored 1692 Hamburg Jacobikirche Schnitger. All other divisions at Saint Mark’s are winded on a very modest 68 millimeters of pressure, including the Pedaal. Flentrop once commented that wind pressure in a pipe organ is analogous to the tension of strings on a violin, with similar effects in the sound.

When I visited in 1972, the 32′ Prestant featured large ears at the sides of the mouths, and a few years later I observed that large wooden rollers had been added between the ears. This was perhaps an effort to make the 32′ sound more audible, as human hearing is very poor in the deep bass. At about 20 cycles per second we feel sound as much as we hear it, and a 32′ pipe resonates at 16 cycles per second. The addition of the rollers increases audible harmonic power to the sound, just as they add harmonic power to very narrow string pipes. Joseph Gabler found an elegant solution to this problem in his organ of 1750 at Weingarten: drawing the 32′ stop also draws the 16′ stop at the same time, making the sound both felt and more easily heard.

Tin was very expensive when Saint Mark’s Flentrop was constructed, the result of a powerful tin mining cartel. Many Flentrop organs utilized copper for larger façade pipes during this time as an alternative to zinc. The colorful patina on Flentrop copper pipes exhibits reddish earth tones and subtle greens. I asked Flentrop how he achieved this, and he laughed. The process was the result of long experimentation, and it involved strongly heating the pipes and applying the urine of cows to the heated metal. Flentrop smiled when he said that the smell in the shop was not at all pleasant. The lovely pastel colors of those copper pipes enhance the deep reds of the mahogany used in the casework, which Flentrop carefully selected from his supplier in Africa.

The full principal chorus of Flentrop’s magnum opus in its 1981 configuration is electrifying in the Praeludium in E Major by Vincent Lübeck <Soundclip 4>. The organ today features some wonderful additions by the shop of Paul Fritts.¹⁹

Paul Fritts and Company Organ Builders

Additions and changes to pipe organs can result in irreparable harm to the original sound. The additions and changes by the Fritts shop, however, are sympathetic to Flentrop’s original concept. They are exceedingly well executed, and Flentrop’s original voicing was left unchanged.²⁰

In 1991 the console action was replaced with a suspended action. Germanic reeds were added at 16′ and 8′ to the Hoofdwerk, and the horizontal reeds were replaced at their original pitches with designs based on the 1762 work of the Iberian organbuilder Jordi Bosch. The original Flentrop reeds have been carefully packed and stored. The addition of a 32′ Pedaal Bazuin on the back wall to the rear of the Pedaal casework is a welcome one in a room whose large windows consume a great deal of bass sound. These alterations will hopefully diminish future appetites for changes to Flentrop’s historic magnum opus.

The precarious life of historic sounds

D. A. Flentrop’s organs are probably a very good representation of the sound of Arp Schnitger, which has very rarely if ever survived in its original form. Between 1953 and 1955 Flentrop undertook a major restoration of the 1720 Schnitger organ at Saint Michael’s Kerk in Zwolle to return it to its original condition, and Biggs recorded that magnificent sound in the 1960s.²¹ History teaches us that original sounds only survive in the very rarest of circumstances, and these are often found in depressed economies where there is no funding for restorations. Historically important sounds quickly disappear with the good intentions of restorers who change wind pressures, temperaments, pitch, and voicing to suit their own ears.²² This is why early documentation is so important, and it can expose later changes.

This article features a sample of scaling and voicing data from D. A. Flentrop’s magnum opus taken in its original form in 1972.²³ It has hopefully provided readers with a better appreciation of the sound of D. A. Flentrop. Astute readers will also no doubt notice that fifty-one years elapsed before I carefully analyzed this data. I should have done this long ago. Tempus fugit, carpe diem.

Notes and references

All images are found in the collection of the author unless otherwise noted.

1. Barbara Owen, E. Power Biggs: Concert Organist (Bloomington, Indiana: Indiana University Press, 1987), pages 128–133.

2. wikiwand.com/en/Dirk_Andries_Flentrop, accessed July 6, 2023. From their reference: Kerala J. Snyder (Spring 2005), Symposium in Honor of Dirk A. Flentrop, Resonance.

3. Michael McNeil, “The Sound of Gottfried Silbermann,” Part 2, The Diapason, January 2023, pages 13–19.

4. Michael McNeil, “1863 E. & G. G. Hook, Opus 322, Church of the Immaculate Conception, Boston, Massachusetts,” The Diapason, Part 1, July 2017, pages 17–19, and Part 2, August 2017, pages 18–21.

5. McNeil, “The Sound of Gottfried Silbermann,” Part 2.

6. McNeil, “The Sound of Gottfried Silbermann,” Part 2.

7. Michael McNeil, “Designing an Historic Reed,” The Diapason, June 2023, pages 14–20.

8. saintmarks.org/music-arts/organs/the-flentrop-organ/ accessed July 12, 2023.

9. “Plainly audible” reverberation is measured at about -26 dB. The -60 dB architectural standard does not take into account the audibility of reverberation in the context of music, and it is also a source of grave disappointment for musicians and organbuilders. The standard needs to be revised for music.

10. Michael McNeil, “1863 E. & G. G. Hook Opus 322: Church of the Immaculate Conception, Boston, Massachusetts,” Part 1, The Diapason, July 2017, page 18.

11. Email the author for Excel files with the Saint Mark’s Flentrop data and/or the Jacobikirche Schnitger data at no charge at: [email protected]. The Schnitger data is derived and graphed from: Heimo Reinitzer, Die Arp Schnitger-Orgel der Hauptkirche St. Jacobi in Hamburg (Hamburg: Christians Verlag, 1995), with restoration by Jürgen Ahrend and data measurements by Cor Edskes.

12. Ibid.

13. McNeil, “The Sound of Gottfried Silbermann,” Part 2; McNeil, “1863 E. & G. G. Hook, Opus 322, Church of the Immaculate Conception, Boston, Massachusetts,” Part 1.

14. Email the author for Excel files with the Saint Mark’s Flentrop data and/or the Jakobikirche Schnitger data at no charge at: [email protected]

15. Michael McNeil, “The Sound of Gottfried Silbermann,” Part 2, The Diapason, January 2023, see Figure 15 on page 14 for an illustration of a wedge for measuring flueway depth.

16. McNeil, “The Sound of Gottfried Silbermann,” Part 2.

17. Email the author for Excel files with the Saint Mark’s Flentrop data and/or the Jacobikirche Schnitger data at no charge at: [email protected]. The Schnitger data is derived and graphed from: Heimo Reinitzer, Die Arp Schnitger-Orgel der Hauptkirche St. Jacobi in Hamburg, (Hamburg: Christians Verlag, 1995), with restoration by Jürgen Ahrend and data measurements by Cor Edskes.

18. McNeil, “The Sound of Gottfried Silbermann,” Part 2.

19. saintmarks.org/music-arts/organs/the-flentrop-organ/.

20. saintmarks.org/music-arts/organs/the-flentrop-organ/.

21. E. Power Biggs, The Organ in Sight and Sound, Columbia Masterworks, KS 7263, ca. 1969. Many examples of Schnitger organs are included in this landmark recording. D. A. Flentrop wrote a primer on classical organ design for the twenty-eight-page book included with this vinyl recording.

22. Flentrop was right when he remarked that I would use my observations of his work to find my own sound. The temptation to modify organs to the taste of the restorer is very strong, and I have regrettably succumbed to that temptation, too. I carefully documented a Wm. A. Johnson organ and described the changes I made to it in these articles, “The 1864 William A. Johnson Opus 161: Piru Community United Methodist Church, Piru, California,” The Diapason, Part 1, August 2018, pages 16–20; Part 2, September, 2018, pages 20–25; Part 3, October, 2018, pages 26–28; and Part 4, November 2018, pages 20–24.

23. Email the author for Excel files with the Saint Mark’s Flentrop data and/or the Jakobikirche Schnitger data at no charge at: [email protected].

Sound clips

1. [00:34] Johann Sebastian Bach, Prelude and Fugue in A Minor, BWV 543, E. Power Biggs, Bach, the Great Preludes and Fugues, Volume 2, CBS Records, 42648, recorded in 1964 at the Busch Reisinger Museum, Harvard University, Cambridge, Massachusetts.

2. [00:30] Charles-Marie Widor, “Andante cantabile,” from Symphonie IV, opus 13, number 4 (1872), James Welch, Magnum Opus, Volume 2, Wilson Audiophile, WCD-8314, recorded in 1981 at Saint Mark’s Cathedral, Seattle, Washington.

3. [01:01] Carl Philipp Emanuel Bach (often attributed to Johann Sebastian Bach, BWV 565), Toccata and Fugue in D Minor, James Welch, Magnum Opus, Volume 1, Wilson Audiophile, WCD-8111, recorded in 1981 at Saint Mark’s Cathedral, Seattle, Washington. Exhaustive research by Michael Gailit has convincingly shown C. P. E. Bach as the most likely composer of this work. See “Exploring the unknown of BWV 565,” The Diapason, Part 1, June 2021, pages 18–19; Part 2, July 2021, pages 12–14; Part 3, December 2021, pages 16–18; Part 4, August 2022, pages 15–17; Part 5, September 2022, pages 19–21; and Part 6, October 2022, pages 15–17.

4. [00:40] Vincent Lübeck, Praeludium in E Major, James Welch, Magnum Opus, Volume 2, Wilson Audiophile, WCD-8314, recorded in 1981 at Saint Mark’s Cathedral, Seattle, Washington.

—It is strongly recommended to use Sony MDR 7506 headphones for the sound clips. Earbuds will not generate bass sound.

Saint Mark’s Episcopal Cathedral website: saintmarks.org.

Flentrop Orgelbouw website: flentrop.nl.

Michael McNeil

Michael McNeil has designed, constructed, and researched pipe organs since 1973. He was also a research engineer in the disk drive industry with twenty-seven patents. He has authored four hardbound books, among them The Sound of Pipe Organs, several e-publications, and many journal articles.

Very few organs survive the depredations of time. Some are the victims of wars and fires, but most are the victims of the good intentions and interventions driven by changing tastes in sound. Those few that have survived such calamities usually have something special about them in their sound or their visual impact. The 1750 Joseph Gabler organ at Weingarten, Germany, is special on both counts—its dramatic chorus makes music come alive, and the architecture of its casework and façade is a stunning tour de force.

The Gabler organ has been criticized since almost the time it was built for its lack of power, having almost a chamber instrument quality. But the Gabler organ has a dramatic flair and musicality that sets it apart from most pipe organs, perhaps teaching us some valuable lessons in tonal design.

Human sensory perception takes notice only of changes. The old joke about cooking a live frog has more than a grain of truth to it. Place a frog in hot water, and it jumps out; raise the temperature of the water slowly, and the frog will take no notice and become dinner. It is the same with sounds. If a sound does not change, we do not notice it or we lose interest. Gabler was a master of the control of change in sound, and this is the heart of the drama in his organ. By way of example, Johann Sebastian Bach’s early composition, the Toccata in E major, BWV 566, requires an organ with a dramatic sound to pull it off, not just a loud organ. Peter Stadtmüller’s 1975 recording of BWV 566 on the Gabler organ takes us to new emotional dimensions <soundclip1>.¹ The Gabler organ’s lessons go to the heart of musicality.

In 1986 Friedrich Jakob and the organbuilding firm of Kuhn published a wonderful book on the Gabler organ at Weingarten. Die Grosse Orgel der Basilika zu Weingarten is available from Orgelbau Kuhn AG, Männedorf, Switzerland.² We are very fortunate that Jakob and Orgelbau Kuhn took the time to write this book and publish it. In an effort to better understand the sound of this instrument, I translated some of its passages with Google Translate, edited the translation as an organbuilder would understand it, and then graphically analyzed the data from the appendix of this book. This is but a very small part of what this book has to offer, and those seriously interested in this organ should purchase this wonderful book.

The current basic specifications of the organ after the restoration by Kuhn are:

Manuals: compass C to c′′′, 49 notes; pitch a′ = 419 Hz at 15 degrees Celsius; wind pressure = 70 mm water column.

Pedal: compass C to d′, 27 notes (originally C to g); pitch a′ = 419 Hz at 15 degrees Celsius; wind pressure = 70 mm water column.

Orgelbau Kuhn restored the Gabler organ between 1981 and 1983. The work was carried out partly in Männedorf, partly in Weingarten, and was summarized as follows:  

A. Static remedial measures:

• Renovation of the gallery floor, partial replacement of supporting beams. 

• Improvement of the Kronpositiv position. 

• Improved support for the bracing of the Positive chest.

B. Removal of added features:

• Demolition of the additional works built in 1954.

• Rebuilding of the Barker machine and restoration of the continuous direct mechanics.

• Rebuilding of the electric trackers for the Kronpositiv, reconnection to the Oberwerk by means of the original conductor blocks.

• Rebuilding of the numerous bellows as well as the newer wind ducts and blower system.

• A reconstructed wind system with six wedge bellows.

C. Normal cleaning and restoration work.

• Make the whole organ wind-tight again.

• Treatment against wood pests. 

• Reworking of all mechanical parts, in particular the axle points. 

• Repair and reconstruction work on the pipework. 

• Tuning in an unequal temperament.³  

Pipework repair

Orgelbau Kuhn performed the normal repairs on pipes that would be expected from centuries of tuning damage. Split pipe seams and loose languids were resoldered, deformed pipe bodies were rounded, and new sections were added to the tops of damaged pipes. 

The effect of the wind system on sound dynamics

The dynamic response of the Gabler wind system is one of most important aspects of its dramatic sound. While measurement data of the wind system is lacking, Orgelbau Kuhn carefully described what they found and what they changed:

The Gabler wind supply in the north tower had already been replaced for the first time in the work of 1861/62. In place of the six original wedge bellows, there were ten box bellows of a new design. Probably in 1912 during the installation of an electric blower the wind system was again modernized by the construction of a large, so-called double-rise bellows.

In the course of the restoration, six wedge bellows were again set up, however, according to practical requirements, with motor operation. The old beams of the bellows chamber did not allow any definite conclusions as to the former position of these six bellows, so free assumptions had to be made.

The original wind duct system, in so far as this had not been done earlier, was practically completely expanded in 1954 and replaced by a new version with cardboard pipes. On the basis of a large number of traces (cut-outs on the casework, color traces on the walls, cut-outs on the beams and on the grids, as well as on the original windchest connections), the course as well as the dimensioning of the Gabler wind duct system could be known.

In three places, where it was obviously not possible to expand, some of the original ducts were preserved. On the one hand, these are the supply ducts to the two Rückpositives under the floor, on the other by a section of the connecting channel above the façade middle flat. This remainder was of particular importance. This is a double channel (57 x 17.5 cm outer dimensions) with a middle wall. The upper part of the duct is marked with “Manual” and the lower part with “Pedal” with a weakly readable red pencil. This was the proof of the actual execution of the wind separation for manual and pedal, which was already required in the contract.⁴

Data on the size of the bellows, ducts, and pallet boxes would allow a calculation of the capacitance (volume) and the inductance (mass, or weight on the bellows) of the wind system. From this data the resonant frequency could be calculated, giving insight into the slow, dramatic risetime of this wind system on full demand. What we do know from the elegant layout drawings of the Gabler organ by Orgelbau Kuhn is that the wind ducts were very long, and the cardboard ducting from 1954 (heard in the 1975 recording by Peter Stadtmüller) was apparently larger in cross section. (“In three places, where it was obviously not possible to expand, some of the original ducts were preserved.”⁴) This means that the internal volume of the wind ducts was larger in 1975, and the sheer length of the ducting indicates a very large internal volume for the entire wind system.

In the 1975 recording we hear a very long, slow surge in the sound of the full pleno driven by a very low resonant frequency in the wind system, and this is a large part of the dramatic sound of the instrument. Such a slow wind system obviously forces a slower tempo, and that is how Stadtmüller interpreted the Toccata in E Major in the glorious acoustics of the basilica. From this we see an essential component of dramatic change: a slow buildup of power when the full organ is played and the wind system is forced to work hard <soundclip2>.¹ The current sound of the organ post-restoration still retains a very dramatic sound, but it is slightly faster, and may be the consequence of the smaller ducting cross sections with less capacitance.¹⁵ When asked about the pipe organ, Igor Stravinsky is reported to have said, “The monster doesn’t breathe.” Although it may have been unintended, Gabler’s gift to us is that he makes the organ breathe.

To put this into perspective, the author took careful measurements in 1996 of the J.-E. & J. Isnard wind system on their organ at St. Maximin, France, and calculated its resonant frequency to be 1.2 cycles per second, a value that correlated very well with actual measurements of the slow, grand surge of this wind system.⁵ Although it is not as long a surge as what we hear in the Gabler organ, the J.-E. & J. Isnard organ at St. Maximin also features a dramatic buildup in power on full organ, the result of high capacitance and high mass in the wind system.

Famous organs with dramatic chorus effects, e.g., the Isnard at St. Maximin, tend to exhibit a purposeful starving of the wind supply where the total area of the toes that can be played in a full plenum are roughly equal to or even greater than the cross section of the wind duct that feeds them. Gabler’s reduction of ranks in the Kronpositiv to alleviate wind starvation, as noted by Orgelbau Kuhn, does indeed suggest that Gabler restricted the cross sections in his ducting. To more fully understand the wind flow of this organ we need measurements of the ducting, pallet openings, channels, and pipe toe diameters for each division.

The effect of the mixture designs on sound dynamics

Pipes are very effective sources of change in sound when they are out of tune (think of the richness of a celeste). We also hear complex dynamic changes in the sound when the speech transients of many pipes combine to form a complex onset of speech in the attack of a chord. The most obvious sources of tonal change are Gabler’s immense mixtures that contain as many as twelve ranks in a single stop. His Sequialters are also constructed of many ranks, and they are scaled exactly like the mixtures. The combination of the Hauptwerk Mixtur, Cymbalum, and Sesquialter contains a vast number of pipes that, as Jakob nicely phrased it, have the effect of a “string choir.”

Multiple ranks at the same pitch do not produce significantly more power (the power increase of doubling the pipes at a single pitch is the square root of 2, or 1.4 times the power). The significant effect is in the depth of the chorus, which is heard as subtle celesting (mistuning) in sustained chords, and which is also heard in the attack of a chord where many pipes speaking together have subtle differences in the speed of their speech and their harmonic content. To some degree these effects are mitigated by the “pulling” effect; pipes of the same pitch placed closely together on the same channel will tend to “pull” each other into tune. But the Gabler chorus has not only many duplicated pitches in a single mixture, it has three such mixtures on the Hauptwerk with limitless possibilities for subtle mistuning effects. The upper pitch ceiling in Gabler’s mixtures is a 1⁄8′ pipe. The preponderance of mixture tone resides in the region from 1⁄2′ to 1⁄8′ pitch, precisely the frequencies to which human ears are most sensitive.

Understanding the sound of the Gabler organ

The appendix of the book contains wonderful data on pipe diameters, mouth widths, and mouth heights (cutups). No data exists on the diameters of the toe openings or the depths of the pipe flueways. This data would allow us to understand the very high cutups of the pipework in this organ. Furthermore, the ratio of the areas of toes to flueways plays a large role in the speech of these pipes. We can only hope that this data will someday be made available. The very useful reed pipe scales in the appendix would benefit from additional data on shallot opening widths, tongue lengths from the tuning wire, tongue widths, and tongue thicknesses, all of which would help us to better understand the sound, especially the very effective Pedal 16′ Bombarde.

Orgelbau Kuhn addressed the low power of the Gabler organ in their description of its scaling and voicing.

The sound of the Gabler organ was already felt as comparatively weak, often as too weak. From the construction period, there were no complaints, because the deadlines and costs were too much in the foreground. Even so, the sound development must have been perceived as partially deficient. This is borne out by the various supplementary technical measures taken by Gabler to increase the sound: the lifting of the roofs by means of cable mechanics, the opening of the side walls of the Oberwerk and the Pedal. All these changes, however, did not benefit much. The reason lay deeper . . . .

The weak sound of the Gabler organ . . . finally led to the construction of auxiliary works, along with stylistic considerations as a result of the altered sound tastes of the time. This resulted in 1912 in the construction of the Seraphonwerk with seven high-pressure registers (150 mm water column) as well as the supplementation of the Kronpositiv by a Cymbal.

What is the source of the relatively weak sound, or rather the relatively low decibel performance of this organ? According to our findings, there are essentially four. The scales of the pipework by Gabler, the sometimes precarious wind conditions, the inhibited sound egress due to Gabler’s compact design, and finally the throttling by the narrowing of the toeholes of the pipes. The number of nicks is irrelevant in this context.

Orgelbau Kuhn pointed to the casework as a source for the low power of the organ.

A[nother] reason for the relative weakness of the sound is to be found in the comparatively small openings for egress of the sound . . . . The big façade pipes are very closely spaced. Apart from the triangle openings around the pipe feet only very narrow slots between the pipes are available for the egress of sound.

Interestingly, images of the façade show that Gabler added carved ornaments between the feet of the façade pipes, further blocking the egress of sound.

Massive, unperforated pipe shades also reduce the egress of sound. While the three problems of scaling, wind supply, and compact construction were already present, the fourth problem only arose as the organ aged: the narrowing of the toe holes due to the very steep angles of the toeboard bore chamfers on which they sat. Last but not least, it was also due to late maintenance. This secondary damage was discovered and corrected in the course of the restoration, while the other characteristics of the Gabler style, of course, remain untouched.⁶

Scaling

The scaling of the Gabler organ is unusually narrow for such a large acoustical space. And unlike the French who scaled their foundations wide but kept the upperwork stop scales narrow, Gabler uses a constant scale, which is narrow in both the foundations and upperwork. Why would Gabler do this? The answer may lie in the layout of his unusual principal chorus, which with its enormous mixtures looks more like an ancient Blockwerk than a typical chorus of his time. Here is Orgelbau Kuhn’s description of the problem:

We can only confirm: Gabler had difficulty with the scales. It is not only in the strings, but in general, that the composition of the scaling is quite narrow. Obviously, he looked at the size of the scales as an absolute one, whereas in reality they were dependent on space. For the giant room of the Weingartner Basilica, respectable distance considerations were appropriate. As a result of these under-nourishing scales, the principal is already near the strings, while the strings are already struggling against the frontier, where a clean, precise, and reliable approach to the fundamental tone is scarcely possible.

That is why Gabler also had to make extensive use of voicing aids, not only of nicking, but also of other voicing aids such as front and box beards. By making use of these aids, at least, all the pipes were able to speak in the fundamental, but a development of the power of the organ was not possible.

Gabler sought to compensate for this scaling deficit through numerous double-ranked and multiple-ranked voices. In the mixture voices, Gabler goes much further. In the Hauptwerk, for example, he built the Mixtur 2′ with ten ranks, the Cimbel 1′ with twelve ranks, and the Sesquialter with nine ranks. Through these chorus effects, Gabler sought to achieve sound power, a power that was not due to the too narrow scales. As we have seen in the Kronpostiv, but also in the Mixturbass, he had wanted to go further in this direction of multiple ranks, but he was, to a certain extent, overtaken by the second evil: he came to the limits of the wind supply. The long wind trunks made an inadequate supply, so that in the course of the work he was forced to cut back on the number of ranks (in the Kronpositiv, for example, a reduction from 18 to 2 ranks).

This struggle for sound and wind is clearly visible to the expert on the evidence in the construction. This desperate wrestling resulted in a great success. But it is clearly a struggle and not a virtuosic play with the principles of organbuilding. The result is a result of the struggle and not artistic design.⁶

The wonderful scaling data in this book was entered into a spreadsheet that normalized the measurements into Normal Scales for pipe diameters, mouth widths, and mouth heights (or “cutups” to a voicer). This graphical presentation allows a much easier interpretation of the data. A set of graphs of the Hauptwerk (Figures 7, 8, and 9) and Pedal (Figures 10, 11, and 12), with commentary, are presented at the end of this article.

The graphs of the pipe diameters (Figure 7) corroborate Orgelbau Kuhn’s assertion that much of the low power was due to narrow scaling. Mouth widths are usually a better indication of relative balances of power, but Gabler used mouth widths that were generally very close to the normalized mouth width scale (one fourth of the pipe circumference), and as such, the normalized mouth width scales (Figure 8) are very similar to the normalized pipe diameters.

The normalized mouth height (or cutup) scales (Figure 9) are remarkable. Gabler’s mouth heights are generally fairly low in the bass increasing to extremely high values in the trebles, so high in fact, that 1⁄8′ pipes are cut up roughly 40% of their mouth widths. The relatively high mouths would suggest pipes with very open toes and flueways, although this data is unfortunately not tabulated. 

Gabler knew how to use very wide scales, but he only used them in his flutes (see the graph of the Hauptwerk, Figure 7). Is Gabler showing us what a Gothic chorus would look like? The chorus effects of these multiple-ranked mixtures are astounding, unique, and very musical. Chorus dynamics, not power, may have been his objective. The subtle imperfections of tuning in these ranks produce subtle celesting on a grand scale. Subtle differences in voicing will produce a rich chorus effect resulting from random differences in the speech onset of the pipes in these mixtures. Gabler may have aimed at the grand sound of a Gothic Blockwerk, not loud, but rich in texture and chorus effects.

Few unmolested pipes remain from the Gothic period, much less complete organs, but one example stands out: the 1475 organ by da Prato in the Basilica of San Petronio, in Bologna, Italy. As recent research shows, this organ is largely original and serves as an elegant example of a Gothic chorus.⁷ The author graphed and combined the data for both the Gabler and da Prato organs. In Figure 1 we see data for normalized pipe diameters, and in Figure 2 we see normalized mouth widths. The data for the da Prato chorus extends to 24′ low F; the 32′ value is a straight-line extrapolation of the 16′ and 24′ da Prato data.8 The Gabler chorus includes the Hauptwerk and Pedal pipes, which extend to 32′.

Scaling data are intrinsically noisy; variations from the intended scale are produced both by the pipemaker and by the person who measures a pipe. Variations of +/- a halftone are normal. The data are remarkable because both sets of data converge on the same intended diameter and mouth scale. We do not know if Gabler imitated the da Prato scales or any other Gothic design, but the similarity of the Gabler and da Prato scales is unquestionable. The dotted black line represents the approximate intended scale, the red lines represent the actual Gabler pipes, and the blue lines represent the actual da Prato pipes.

Gothic pipework (Figure 3) from an organ by an unknown builder in Ostönnen, Germany, exhibits an unusual design characteristic also seen on the façade pipes of the Gabler organ (Figure 4). Figure 3 shows an extension of the upper lip at the sides of the mouth (red arrow), making the mouth width slightly narrower than the width of the flueway.⁹ We do not know if Gabler was taking his cue from a Gothic model, but the comparison is interesting.

Voicing

The minimum data set to understand the voicing of an organ includes the mouth height (“cutup”), toe diameters, flueway depths, treatment of the languids (bevel angles and types of nicking), and presence or absence of ears and other such devices. Like the da Prato organ of 1475, the Gabler organ exhibits no ears on the façade pipes and presumably none on the internal pipes of the principal chorus. Orgelbau Kuhn provides data on cutups, but not on toe diameters or flueway depths. Voicers adjust toe diameters and flueway depths to affect the flow of wind for more or less power. Voicers raise cutups to make the pipe tone smoother with less harmonic bite. More wind, from either the toe or flueway, will increase power and make the tone brighter with more harmonic bite. A more powerful and brighter timbre can be made smoother again with higher cutup. Hence, it is important that we know all three variables—cutups, toe diameters, and flueway depths—if we are to understand the voicing. We have only mouth height data. 

A common precept of neo-Baroque voicing was the rule that the mouth height should be 1⁄4 of the width of the mouth. There is, of course, no basis for this in historic work, nor is there any theoretical basis, and it produces a rather strident timbre in most pipework. The normalized mouth heights of the Gabler organ, seen in Figure 5, are remarkable. Only in the bass do they approach a value which produces a height 1⁄4 of the mouth width (this occurs when the normalized mouth height scale in halftones is the same as the normalized mouth width scale in halftones). But as the pitch ascends for the Gabler pipes, so do their normalized mouth heights, until at the highest 1⁄8′ pitches the mouths are very high, about 40% of their mouth widths. Also of note is that the treble mouth heights of the principal chorus are almost as large as the mouth heights of the very wide flutes in the Hauptwerk. The same trend is seen in Figure 6 of the da Prato mouth heights, but the typical da Prato values are lower, a reflection of that organ’s lower wind pressure. The highest mouths in the da Prato graph are also those of its flutes. Gabler’s treatment of mouth height looks very much like the Gothic work of da Prato, adjusted for higher wind pressure.

Reiner Janke sent the author photos of pipe mouths from the 1743 choir organ at Weingarten, also built by Gabler. These photos show very generous flueway depths and deep, fine nicking. Although we do not have toe diameters to confirm this, it may be reasonable to assume that Gabler’s high mouth heights in the treble reflect a desire for a more ascending treble.

Orgelbau Kuhn limited their analysis of the voicing to the presence of nicking and the method of tuning:

While ‘tuning’ means the mere regulation of the pitch, the ‘voicing’ includes the processing of all partial aspects of a musical tone, including the loudness, the tone color, the tone accent, or the transient response. This eminently artistic work is generally performed only when a new organ is being built, or when a major rebuilding is carried out.

A restoration, especially if it also includes changes or regressions in the wind supply system (bellows and wind duct system), also causes a new voicing of the pipework. It is necessary to think philosophically about the original Gabler voicing, and it would be wrong to assert that it had remained intact, for the intervening interventions were too great. Of course, we did studies on other Gabler organs, but also on instruments of other South German masters such as Holzhay and Höss, but there were no exact models for the voicing in the Weingarten types, one simply had to work with the existing pipe material. The technical procedure can be easily rewritten. First, the pipes were normalized and repaired where necessary (open solder seams and loose languids soldered). The languids were then carefully placed in the correct position for an optimal response to the pipe in the fundamental. In the rest, as little as possible was changed.

Gabler has made extensive use of nicking. This can be seen in the non-speaking but voiced façade pipes c′–d′ of the Kronpositiv, which are completely unchanged. In addition to the original nicking of Gabler, the main body of the pipes also contains nicking of other handwork. It turned out to be impossible to assign only the newer nicking, but to leave the Gabler nicking unmarked. So it was decided not to work the languids; the insertion of new languids was not considered at all . . . .

The labial bass pipes are provided with cleanly inscribed tuning slots proportioned to the pipe diameter up to the 2′ position. Attempts have shown that stops without these tuning slots could not be tuned over the entire range of octaves. These tuning slots are therefore to be regarded as original. In contrast to later practices, however, these tuning slots are only scribed and not fully enrolled.

Tuning 

The absolute pitch is A = 419 Hz at 15 degrees Celsius. The original temperament was very similar to Gottfried Silbermann’s meantone. It was characterized by eight not pure, but good, major thirds, eleven tempered fifths, and one large Wolf fifth on D-sharp to G-sharp. It had an equal temperament fifth at C, extending to -12 cents at G-sharp and extending to +5 cents at D-sharp.

The current milder tuning deviates from the original meantone and has an equal temperament fifth at C, extending to -9 cents at G-sharp and extending to +1 cent at D-sharp.10 It is not known if the Musical Heritage Society recording of 1975 reflects Gabler’s original tuning or something closer to the present tuning.1 Like Gottfried Silbermann, Gabler uses high cutups in his voicing for a less strident timbre, and this works well with meantone temperaments, mitigating the harshness of the more dissonant intervals.

Reflections

Friedrich Jakob reflected on the sound of the Gabler organ:

How is the sound of the Gabler organ to be characterized? We are confronted with the general problem of describing sound with words. With features such as warm, round, pointed, sonorous, bright, and so on, no exact statements are possible. Still, be tempted.

The Gabler organ is certainly not a forceful organ. Power and brilliance are missing in comparison to the normal large organ. The sound is somewhat reserved, veiled, poetic, and pastel colored. The tremendous multiple ranks of the mixtures give the effect of a string orchestra. Minimal deviations of the individual voices do not result in any false tone, but a larger range of the right one. It was very important to leave the organ intimate in character with the chamber music and not to have a wrong symphonic influence. But since everything is wind-tight again, and every pipe is speaking the fundamental, the organ sounds a little more powerful than before.¹¹

The claim has been made that Gabler did not understand the principles of scaling as they relate to larger rooms, and Jakob describes very convincing evidence that Gabler struggled with the power. But the inflection point of Gabler’s constant scale at 1⁄2′ demonstrates that Gabler had a good grasp on the effect of distance on the sound absorption of higher frequencies. Tones extending from the deep bass up to the pitch of a 1⁄2′ pipe will carry very effectively over long distances, but pitches above that point will lose energy in their interaction with the atmosphere, so much so that the sound of a 1⁄8′ pipe will lose 5 dB in power at 500 feet.¹² One halftone of scaling is equivalent to 0.5 dB of power, so this means that 10 halftones of wider scaling must be used at 1⁄8′ to compensate for the atmospheric losses at 500 feet. Gabler widened his mixture pipes by 8 halftones from 1⁄2′ pitch to 1⁄8′ pitch. The length of the Basilica of Saint Martin and Saint Oswald at Weingarten is 102 meters, or 335 feet. Gabler has compensated very well for the distance losses. The absolute values of these scales are indeed much narrower than what we would typically find in rooms of this size, but the mathematics show that Gabler was cognizant of the effects of large distances. But Jakob also convincingly demonstrates that Gabler was not satisfied with the power, went to some trouble to correct it, and ultimately failed in the effort.

Figures 7 and 8 show the diameter and mouth width scales of the Hauptwerk. Note how much wider Gabler scales his flutes relative to the principal chorus. These flutes are quite powerful and provide an extremely effective contrast to the mixture plenum. A wonderful example of this contrast can be heard in Ton Koopman’s interpretation of the Bach Concerto in A Minor after Vivaldi, “Allegro,” BWV 593 <soundclip3>.¹⁵ Here Koopman demonstrates that Gabler’s flutes can cut through the principal chorus. While typical interpretations of this concerto use contrasting principal choruses, Koopman’s performance gives a clarity and beauty to this concerto that can only be heard with Gabler’s tonal balances. Gabler’s organ, if it is not powerful, is extremely musical, and we can learn much from his example, all of it applicable to organs with more power.

To summarize, some of Gabler’s musicality derives from the intense chorus effects of the mixtures with their many ranks, the many duplicated pitches, and the subtle depth created by the mistuning of those multiple ranks. Multiple ranks do not significantly increase power, but they do increase the sense of chorus.

Another aspect of the musicality of the organ resides in its very slow wind response, which takes the form of a dramatic surge to full power when the organ is playing a full pleno. Another effect that produces a slower wind is a high resistance in the wind system, and Jakob mentions this in his description of the Kronpositiv ducting, which was so restrictive that Gabler was forced to remove a large number of ranks on that chest. Many classical organs feature wind trunks that were purposely designed with smaller cross sections to barely flow the required wind, or even starved the wind to a degree.¹³  

Finally, Gabler employed very large scales in the deep bass of the Pedal. Along with the robust Bombarde 16′, the Pedal produces a tactile effect underpinning the modest power of the manual pleno. The overall effect of the Gabler organ is intensely dramatic without being at all overbearing. To reduce this to a basic philosophy, Gabler was a master of designing for a sense of change in the sound, both aural and tactile. The acoustician R. Murray Schafer observed that “. . . a sound initiated before our birth, continued unabated and unchanging throughout our lifetime and extended beyond our death, would be perceived by us as—silence.”¹⁴ His point was that for a sound to have drama, to grab our attention, it must change: change in pitch with the subtle mis-tunings of his multiple-ranked mixtures, and change in power with the slow rise in the pressure of the wind. The organ at Weingarten is the singular achievement of a master, and even if by today’s standards the overall power seems modest, we can use Gabler’s lessons to great advantage.

 

Excellent recordings exist of the restored Gabler organ.¹⁵ See also Youtube for a cut from this CD: Präludium & Fuga C Moll, BWV 549: www.youtube.com/watch?v=hWWtpS-yvKI.

 

The following normalized graphical data for the Hauptwerk and Pedal were constructed from Jakob’s data. Email the author for a copy of the original Excel file with the data and normalizations, which also includes the Oberwerk: [email protected]. Readers interested in the theory behind these normalizations may refer to The Sound of Pipe Organs.¹²

Hauptwerk data (see Figures 7–9)

Jakob’s claim that narrow scaling is responsible for much of the low power of this organ is amply supported by the normalized pipe diameter data. Gabler is using a “constant scale,” where all pipes speaking the same pitch are the same scale, regardless in which stop they appear or in which part of the keyboard compass they appear. This constant scale averages -7 halftones from 16′ to 1⁄2′ pitches, then increases rather linearly to +1 halftone at 1⁄8′ pitch. The normalized mouth widths seen in the next graph follow a similar trend because Gabler scaled his mouth widths very close to 1⁄4 of the pipe’s circumference, the basis of the normal mouth width scale.

Gabler’s normalized mouth heights are remarkable in their deviation from the pipe diameter and mouth width Normal Scales, and they tell us something about Gabler’s intentions in power balance from the bass to treble. High mouths are a tool of the voicer to achieve a smoother, less bright tone, or alternatively, a more powerful tone when the pipe is winded with larger toes or larger flueways. Gabler uses the mouth height as an independent variable, perhaps to achieve an ascending treble power in the plenum. Data on the toe diameters and flueway depths would give us a deeper understanding.

The diameter and mouth scales of the Hauptwerk 8′ and 2′ flutes are very wide. The Gabler flutes are very smooth and liquid in tone and have very high mouths when plotted on the Normal Scale, but those mouth cutups would appear low when looking at the actual pipes because the diameter and mouth scales are very wide. Gabler knew how to use very wide scales, but he only applied such scales to the flutes, perhaps suggesting that his narrow principal chorus scales were an intended result, even in this large acoustic.

Pedal data (see Figures 10–12)

In Gabler’s Pedal we also see a constant scale, but it has a different shape, averaging about +3 halftones at 32′ pitch, descending linearly to about -7 halftones at 2′ pitch, and thereafter remaining roughly flat at that scale up to 1⁄2′ pitch. These wide scales in the deep bass are the source of the tactile effect in Gabler’s sound. Human hearing becomes dramatically less efficient in the bass; at about 20 Hz we hear and feel a sound at about the same level. Below that frequency we tend to only feel the sound. The frequency of a 32′ pipe is 16 Hz and is much more felt than heard. Note the very wide scales of the 16′ Octavbass. It is powerful enough to achieve a strong tactile effect; also note its very high cutups, which imply full wind at the toes and flueways. 

Like the Hauptwerk, the Pedal mouth widths are similar in normalized scaling to the pipe diameters and tell a similar story. Also like the Hauptwerk, the Pedal mouth heights dramatically ascend with higher pitch. 

The Pedal Bombarde is full length with rectangular wooden resonators. The effective scale of a wooden resonator is its diagonal measurement, i.e., the width of its standing wave, and this reed measures a very generous 240 mm at low C. Combined with the tactile character of the deep bass flue pipes, the Bombarde is a very strong component of the drama achieved by the Gabler chorus.

Notes:

1. Peter Stadtmüller, Toccata in E major, BWV 566, J. S. Bach, Musical Heritage Society MHS 3195, Gabler organ, Basilica of Saint Martin and Saint Oswald at Weingarten.

2. Friedrich Jakob, Die Grosse Orgel der Basilika zu Weingarten, Geschichte und Restaurierung der Gabler-Orgel, Verlag Orgelbau Kuhn, Männedorf, Switzerland, 1986, 146 pages. The book and shipping totaled 73.00 Swiss Francs. At this time Kuhn is only able to receive funds wired to their account, which makes the book rather expensive to those of us who live across the Atlantic Ocean. Email Orgelbau Kuhn AG: [email protected]. Website: www.orgelbau.ch.

3. Ibid., pp. 40–43.

4. Ibid., pp. 55–56.

5. My statement of the “. . .motions of the bellows plates. . . to be ≈ 1.25 Hz” for the Isnard wind system in The Sound of Pipe Organs, page 108, has errors that I missed as a result of the closeness of the calculated resonance in Hz and the measured period of the response in seconds. My measurement of the bellows response at 1.25 seconds represented three motions of the bellows, down-up-down, which is 1.5 times the period of the wind surge. Therefore, the correct period, one cycle of two motions, down-up, is 1.25 / 1.5 = 0.83 seconds. Inverting that (1 / 0.83 seconds) gives us 1.20 Hz, or cycles per second, which perfectly correlates to the correctly calculated resonant frequency of the system.

6. Die Grosse Orgel der Basilika zu Weingarten, pp. 72–79.

7. Oscar Mischiati and Luigi Ferdinando Tagliavini, Gli Organi della Basilica di San Petronio in Bologna, Pàtron Editore, Bologna, 2013, 577 pp.

8. Michael McNeil, A Comparative Analysis of the Scaling and Voicing of Gothic and Baroque Organs from Bologna and St. Maximin, e-publication, PDF, Mead, Colorado, 2016. Email the author for free copy:
[email protected].

9. See Youtube video of the organ at Ostönnen: www.youtube.com/watch?v=YxmsZ5ksaVY. Also see the Youtube panoramic video of the Gabler organ in which you can zoom in to see the same treatment of the façade pipe mouths: www.panorama-rundblick.de/gabler-orgel-weingarten. Click on the red arrow to move to the front of the console to see the 32′ façade.

10. Die Grosse Orgel der Basilika zu Weingarten, p. 78.

11. Ibid., p. 79.

12. The Sound of Pipe Organs, pp. 13–14.

13. Ibid., pp. 119–127. See the example of the wind flow calculations for the Isnard organ at St. Maximin.

14. R. Murray Schafer, The Tuning of the World, Alfred A. Knopf, New York, 1977, p. 262.

15. Ton Koopman, J. S. Bach Orgelwerke II, Gabler-Orgel, Basilika Weingarten, Novalis CD, 150 020-2, 1988.

 

Photo: The 1750 Joseph Gabler organ, Basilica of Saint Martin and Saint Oswald, Weingarten, Germany (photo credit: Thomas Keller; see the source in Note 9)

Michael McNeil

Michael McNeil has designed, constructed, voiced, and researched pipe organs since 1973. Stimulating work as a research engineer in magnetic recording paid the bills. He is working on his Opus 5, which explores how an understanding of the human sensitivity to the changes in sound can be used to increase emotional impact. Opus 5 includes double expression, a controllable wind dynamic, chorus phase shifting, and meantone. Stay tuned.

Editor’s note: The Diapason offers here a feature at our digital edition—two sound clips. Any subscriber can access this by logging into our website, click on Magazine, then this issue, View Digital Edition, scroll to this page, and click on each <soundclip> in the text.

Part 1 of this series appeared in the December 2022 issue, pages 12–17.

Deductive logic is tautological; there is no way to get a new truth out of it, and it manipulates false statements as readily as true ones. If you fail to remember this, it can trip you—with perfect logic. . . . Inductive logic is much more difficult—but can produce new truths.²¹

A range of voicing styles

In Part 1 we discovered the features of Silbermann’s pipe construction and voicing that make his sound unique. What could we learn by comparing Silbermann’s voicing to other styles? A great deal, as it turns out, and to do this we will take a much deeper dive into the voicing parameters shown in Part 1.

Toe diameters

Toe diameters control power by limiting the flow of wind and reducing the pressure in the pipe foot. We often hear the term “open toe” voicing, but what does this really mean? And how could we compare the very different regulation of toes in Germanic and French voicing? Tables of raw pipe toe diameters do not convey the intent of the organbuilder or allow us to make meaningful comparisons. 

In 1972 Dirk Flentrop advised me that a starting point for estimating the diameter of a pipe toe is the square root of its resonator diameter, and that is assuredly not the widest possible toe.²² Building on this idea I devised what I call a toe constant “c” to compare the flow of wind through pipe toes. Flentrop’s advice, the square root of a pipe’s diameter, defines a toe constant “c” of exactly 1. Interestingly, the toe constant for Andreas Silbermann’s pipe shown in Figure 2 in Part 1 is 0.97, virtually identical to Flentrop’s guidance.

Toe constants can be larger or smaller to suit the acoustics and the power balances within a chorus, and they can vary for different levels of wind pressure. For example, if we want more power at the same pressure, we will use larger toe constants and larger toes, and vice versa for less power. If we want the same power at a higher pressure, we will use smaller toe constants.

The toe constant also needs to take into account the larger or smaller flows of wind needed by different mouth widths. Mouth widths are specified as a fraction of the pipe circumference. A 2⁄7-width mouth is wider than a 1⁄4-width mouth on the same pipe, and it will need a larger toe to feed more wind to the wider flueway of that mouth. I added a term to Flentrop’s advice (he typically used 1⁄4 mouth widths) to adjust the wind required to feed wider or narrower mouths. For example, Silbermann’s toe constants in Figure 8 (page 17) have values of 1 at 2′ pitch, but those values reflect toes that are larger in diameter than the square root of their pipe diameters—those toe diameters are adjusted proportionally larger to provide the extra wind needed by the flueways of Silbermann’s wider 2⁄7 mouths. Note 23 shows the very simple equation for calculating the toe diameter from the pipe diameter, mouth width fraction, and toe constant. 

The toe constant now allows us to visually compare the relative flow of wind among voicing styles and wind pressures for pipes of any scale or mouth width. While the term “open toe” is vague, the toe constant is quantifiable.

Silbermann adjusted the toes of the Freiberg Dom chorus in Figure 8 for more wind flow in the bass and treble. None of the toe constants are below Flentrop’s guidance of 1. The highest trebles at 1⁄8′ pitch have reduced wind flow, and we will soon see a very interesting explanation for this. 

Note the regularity of Silbermann’s toe constants. All pipes of the same pitch have the same toe constants and wind flow regardless of where they appear in the stops or the compass. The mixtures appear to have slightly larger toes, perhaps as a compensation for their slightly narrower scale, indicating that Silbermann wanted the same power from the mixtures but with the brighter timbre of their narrower scale. 

Such regularity is extremely rare, and it suggests that Silbermann calculated his toe diameters prior to voicing. These data also suggest the idea that he approached organ design from an inductive viewpoint, using data to infer the design rules with which he achieved his sound. Some might criticize this regularity, but we might also learn something from it. Let’s see how other builders controlled their pipe toes.

Figure 14 (page 14) shows the toe constants for a vast range of voicing styles, most of which represent 4′ Octave stops in the main manual division. All of these styles have toe constants entirely above a value of 1 except for two cases: the classical French voicing of the Isnards and the high treble of D. A. Flentrop’s example. 

The data in the pink line are from D. A. Flentrop’s 1977 organ at California State University, Chico, voiced on a low pressure of 66 mm. This organ was built at a time when all classical voicing was considered “open toe,” but readers may be surprised to see that Flentrop’s voicing does not remotely use the most open toes in Figure 14. He deviated from his guidance (the square root of the pipe diameter) as needed, extending above 1 in the bass and mid-range, and dropping below 1 in the highest treble. The acoustically dry concert hall in which the Flentrop resides is also the smallest of the acoustics in Figure 14. His wind pressure is the lowest in Figure 14, and this might suggest the use of the most open toes, but Flentrop was willing to restrain these toes for a more restrained treble power.

The data in the orange line are from Silbermann’s organ at Großhartmannsdorf on 90 mm pressure, and the data in light blue are from his organ at Reinhardtsgrimma on 70 mm pressure. Note that Silbermann uses much more open toes on lower pressure. The Großhartmannsdorf data is virtually identical to the toe constants at the Freiberg Dom in Figure 8, evidence that these toes may have been calculated to accommodate the similar wind pressures of these organs. 

The data in the dark blue line are from the 1774 Isnard organ at Saint Maximin on 83 mm pressure. Here we have mid-range toe constants that dip well below a value of 1, and with this visual graphic we can now see what is meant by “closed toes” in this French voicing example.

The individual data points in the pink boxes are from the 16′ Hauptwerk Principal in Arp Schnitger’s 1688–1692 organ at the Jacobikirche in Hamburg on 80 mm pressure, one of the largest acoustics in the Figure 14 examples.²⁴ These are widely open toes, and they also compensate for the wind pressure drop that occurs in the conductors between the windchest and the pipe feet of these offset façade pipes. Principal pipes that sit on the windchest of the Schnitger organ have toe constants closer to those of Silbermann at Reinhardtsgrimma in the light blue line. All of the other pipes in Figure 14 from 4′ to ¼′ pitch sit directly on the windchest without pressure losses.

The data in the yellow line are from the 1863 organ by E. & G. G. Hook at the former Immaculate Conception Catholic Church in Boston. This Romantic organ is voiced on 76 mm pressure, and it may surprise readers to see that it has the most “open toe” voicing in Figure 14 for pipes sitting directly on the windchest. 

The toe constants in Figure 14 show us that all of these organbuilders adjusted the toe to regulate wind flow and power. The toe constant gives us the means to make meaningful comparisons.

Flueway depths

Flueway depths control power. Flueway data are essential for understanding organ sound, but they are exceedingly rare. Figure 15 shows how flueway depths are measured. Figure 16 shows flueway depths for the same pipes shown in Figure 14. Figure 9 shows the very deep flueways of the Freiberg Dom Silbermann.

The Flentrop data in the pink line in Figure 16 explore the lower limits of flueway depths with excellent musical effect on 66 mm pressure. Figure 17 shows the bright, harmonically rich, “instrumental” voicing of a Flentrop pipe from about 1980. In addition to the two obvious deeper nicks and the extremely light nicks in the middle of the counterbevel, note the unusual bold nicks placed at the far right and left sides of the flueway, the absence of ears, and the moderate cutup. Flentrop’s harmonically rich voicing contrasts with the much less bright vocale style of voicing.

The data in the yellow line from the Romantic Hook organ explore the upper limits of musicality. These pipes are voiced on 76 mm pressure with many bold nicks. The Flentrop and the Hook data give us some idea of the range of historic flueway depths.

The Silbermann flueways in the orange and light blue lines represent the range of Silbermann’s flueway depths for the range of pressures represented by these data. Note that at 90 mm of pressure at Großhartmannsdorf, Silbermann’s flueways are virtually identical to the flueways of the Freiberg Dom chorus in Figure 9, more evidence suggesting calculation of flueways for a specific wind pressure. The treble flueways are as deep as those found in the Hooks’ Romantic voicing.

It is interesting that Silbermann adjusted his flueways shallower at lower pressure and deeper at higher pressure, an unexpected relationship. Open flueways without bolder nicking have a breathy component to their sound, and Silbermann may have adjusted his flueways shallower in smaller, more intimate acoustics to minimize that effect. The high frequencies that characterize breathiness are absorbed by the atmosphere, and distance reduces their audibility in larger acoustics.

The restorers of the Isnard organ interestingly noted that the very generous flueways in the dark blue line were more “closed up” relative to typical French voicing. As we will later see, the Isnards appear to have adjusted their flueways and toes to achieve remarkable balances. 

The individual data points in the Figure 16 pink boxes are from Schnitger’s 16′ Principal on 80 mm pressure. These Schnitger flueways correlate extremely well to the deepest flueways used by Gottfried Silbermann. All of the illustrated Schnitger data were taken by Hans Henny Jahnn in 1925.

For those interested in Schnitger’s work, Figure 18 shows a subset of Jahnn’s original data (he took data on every pipe in this stop). The data in the pink font in Figure 18 are represented in Figure 16 by the pink boxes. 

The single pink triangular data point well below the Flentrop data at 1′ pitch is the razor-thin flueway of the neo-Baroque pipe illustrated in Figure 3 of Part 1; it is voiced on 65 mm pressure with a very low cutup. The data clearly show that this flueway does not remotely resemble any historic voicing style in Figure 16, and the reason for that brings us to cutups.

Cutups

Cutups (also known as “mouth height”) are often described as some fraction of the mouth width. While using a mouth width fraction with dividers to scribe preliminary cutup heights on upper lips has some practical value during voicing, it has been shown that the tonal effect of cutup has absolutely nothing to do with the width of the mouth.²⁵

Cutups are adjusted to control timbre, and cutups will be higher for the same timbre at a higher level of power. We will get continuously less bright timbres as cutups are increased at any specific power. Cutups that are too low will cut the vortex in the flueway at too high a frequency for the resonator to quickly respond, and the fundamental will form more slowly.

Some neo-Baroque efforts to recapture historic voicing invoked a recipe where cutups were required to be ¼ of the mouth width and toes were vaguely required to be “open.” This recipe is a perfect example of an untested opinion based on deductive logic (which the author, too, naively embraced in his Opus 1).

Pipes voiced with deep flueways, wide-open toes, and low cutups will either screech with powerful harmonics or overblow to the octave on higher pressures. Closing the flueway takes away the strident screech, but it also strangles the power of the fundamental. Using the neo-Baroque recipe of wide-open toes and ¼-cutups, the voicer was forced to close the flueway to extremely small values. Without reducing the wind pressure, this was the only option left to the voicer. A typical compromise in this style of voicing allowed for some stridency in the timbre to preserve some modest power in the fundamental, and in this condition the pipe was often too close to overblowing. The result was the slow, gulping speech and thin fundamental so often heard in early Orgelbewegung movement voicing. 

The solution to this problem is by now quite obvious to the reader—adjust the toe and/or the flueway (according to your preferences) until the desired fundamental power is achieved, and then raise the cutup to get the desired timbre and prompt speech. If Silbermann had used ¼-cutups at the Freiberg Dom, the values of his Normal Scale mouth heights in Figure 10 would look identical to the values of his Normal Scale mouth widths in Figure 5. Unsurprisingly, Silbermann’s high cutups bear no relationship at all to his mouth widths. 

Figure 19 shows cutups for the same pipes shown in Figure 16. The data in the pink line are from the Flentrop organ voiced on 66 mm pressure. Cutups trend higher on higher wind pressures, depending, of course, on the regulation of toes and flueways. The Flentrop data represent the lowest wind pressure in this graph with a harmonically rich, restrained power in the smallest acoustic among these examples. The lower cutups of the Flentrop voicing are no surprise.

The data in the orange line are from Silbermann’s organ at Großhartmannsdorf on 90 mm pressure, and the data in light blue are from the Reinhardtsgrimma organ on 70 mm pressure. This is the same data we saw in Part 1 where Silbermann used higher cutups at higher wind pressures to maintain similar timbres. Again, it is no surprise that these cutups are higher than Flentrop’s lower pressure voicing. In Figure 19 the wind pressures appear just to the right of the data lines, and in the treble they progress smoothly from lower cutups on lower pressure to higher cutups on higher pressure.

The data in the dark blue line are from the Isnard organ on 83 mm pressure. The Isnard cutups follow the same wind pressure trend as the Silbermann data and lie mostly between them. We might expect the 83 mm pressure Isnard cutups to lie closer to Silbermann’s 90 mm cutups. Figure 14 tells you why they do not (hint: look at the Isnard toe constants and the implied pressure drop in the pipe feet).

The individual data points in the pink boxes are from the Schnitger example on 80 mm pressure. The treble cutups from 4′ pitch reflect significant power in this 16′ stop, as would be expected from its copiously winded toes and flueways in Figures 14 and 16. 

The data in the yellow line are from the Romantic Hook organ voiced on 76 mm pressure. The highest treble data lie just above Silbermann’s 70 mm pressure data as expected. But the bass and mid-range cutups are much higher than expected, and this reflects the higher bass power of a Romantic organ, a power fed by the largest toes in Figure 14 and the deepest flueways in Figure 16. The Hook does not have the highest wind pressure in Figure 19, but it is a good example of getting more power out of larger toes and deeper flueways (and bold nicking). 

Higher cutup with more wind gives us power, and a good example is the Pedal 32′ Bourdon at Saint Ignatius Catholic Church in San Francisco, California. This large room seats about 1,800 people, and as a 64′ resultant this Bourdon is able to cause visible vibrations in the pews at its 8 Hz pitch. It has a scale of 535 mm on the diagonal, a mouth width of 349 mm, a 4.0 mm flueway, a 100 mm toe, and it is winded on 203 mm (8 inches) pressure. The power of this pipe is reflected in its cutup of +20 HT (203 mm average, arched). This cutup is literally way off the top of the graph in Figure 19. You do not hear such a sound; you feel it. On his next visit to the Atlantic City organ, John Bishop might regale us with the cutup of the Pedal 32′ Contra Diapason on 20 inches of pressure!

Toe and flueway ratios 

Areas are more important in many ways than diameters and depths, and the ratio of the toe area to the flueway area strongly affects speech articulation (also known as “chiff”). Figure 20 shows these ratios for the same pipes in Figure 19. Figure 11 shows the ratios for Silbermann’s Freiberg Dom organ. 

Ratios larger than 1 mean that we are trending toward more “open toe” voicing, where a pipe’s toe area is larger than its flueway area. A ratio less than 1 means that we are trending toward more “closed toe” voicing, where the toe is smaller and will flow less wind than the flueway. Examples of pipes with ratios far below 1 with very closed toes feeding especially deep flueways are common in theatre organs on exceptionally high wind pressures.

Articulation provides percussive clarity to rhythm, but lower ratios will reduce articulation. Wind pressure builds more slowly in the foot with smaller toes, and a slower buildup of pressure will make articulation more gentle and less percussive. Ratios above 1 tend to accentuate more articulate speech, and this is why we hear more articulation with “open toe” voicing. Classical French voicing, with its closed toes, deeply open flueways, and lower ratios will have much less articulation than North German voicing and less response to the touch of the key. 

All of the pipes below 1′ in pitch in the entire Grand Orgue principal chorus of the Isnard organ at Saint Maximin originally had ratios so close to 1 as to suggest that it was a purposeful goal.26 It is an exception in classical French voicing with its more moderate flueway depths, and it exhibits gentle articulation. In this soundclip we hear the exquisite articulation of the Isnard Positif 8′ Montre in Louis Marchand’s Tibi omnes angeli. <soundclip 4>
From the middle of the compass to the high treble, the toe constants of this stop range from 0.6 to 1.2, and the toe/flueway ratios range from 0.7 to 1.8.27

In Figure 20 we see that Silbermann’s organ at Großhartmannsdorf has ratios that never drop below 1, and they closely parallel the French voicing of the Isnards. The ratios of the Freiberg Dom organ in Figure 11 on a similar wind pressure are virtually identical, and we might gain some insight from this data to explain why the toe constants in Figure 8 drop at 1⁄8′ pitch. The ratios in Figure 11 continue to rise right up to 1⁄8′ in pitch, and this means that the flueways in Figure 9 have increasingly more wind from the toes as the pitch rises. The toe constants at 1⁄8′ pitch in Figure 8 obviously drop in their relative flow of wind, but those toes are still feeding increasingly more wind to much smaller flueway areas (i.e., the flueway areas are dropping at a faster rate than the toe areas). This is very strong evidence that Silbermann was calculating toe and flueway areas. 

Silbermann’s lower pressure organs have much higher ratios, i.e., they are much more “open toe,” and the more unmolested examples tend to exhibit more articulate speech. This is why the Orgelbewegung, which prized clear articulation, emphasized “open toe” voicing on lower wind pressures. The movement got it partly right, that more open toes will emphasize articulation, but the factor that matters more is the ratio, not the diameter of the toe. D. A. Flentrop’s voicing does not have the most open toes in Figure 14, but with the most closed flueways in Figure 16, the Flentrop ratios are generally the highest in Figure 20, and the articulation of this Flentrop is very clear.

Arp Schnitger did not use heavy nicking. His ratios in Figure 20 are high in both bass and treble, and his more unmolested pipes have clear articulation.

Fine nicking will reduce articulation, but bold nicking will eliminate it in all conditions. (Nicks likely stabilize the formation and position of the vortex on the languid edge.) About 90% of the pipes in the Isnard organ have no visible nicks on their languids. Much of the very fine nicking occurs on the separate mutations, giving them a smoother legato as a solo voice.²⁸ French Romantic voicing evolved from the deep flueways of Classical French voicing, and it employed bold nicking to achieve a smooth Romantic legato. Nicking also has the same effect as raising the cutup, and the sound is less bright after adding nicks, i.e., nicking permits lower cutups for the same timbre. The Hook ratios in Figure 20 are high, but the bold nicking of the Romantic Hook voicing completely suppresses its speech articulation.

While on the subject of Romantic voicing we should note that this style often employs a tuning device, known as a Reuter tuning slot, which greatly reduces articulation. The tuned length is achieved by cutting a slot into the pipe that does not extend to the top of the pipe. If you want clear articulation, pipes need to be cut dead length or fitted with tuning slides that extend to the top of the pipe. Anything that makes the tuned length of the pipe indeterminate will reduce articulation. Classical French façade pipes with extreme overlengths and multiple cutouts at their backs to achieve the correct pitch have little articulation, and this is consistent with their closed toe voicing style. Articulate Germanic voicing trends toward dead-length tuning, which is also typical of Silbermann’s work. 

Ears 

There are more details that affect voicing in more subtle ways that are not within the scope of this article, but we should address one of them: ears. Romantic and neo-Baroque voicing make consistent use of ears because they significantly increase the power of the fundamental by about 1.5 dB. This is not trivial, and it represents a scaling increase of three halftones. But ears also come at a price with a strong increase in the power of a few discrete higher harmonics, and the resulting blend is worse. The blend of pipes with high cutups and few harmonics will be less impacted by ears. The spectral data on the change in power and timbre caused by ears is shown in the author’s book.²⁹

Classically inspired voicing

We can readily grasp the Silbermann brothers’ use of deep flueways from their exposure to French voicing. But the deep flueways of Arp Schnitger’s work shown in Figure 18 are unexpected. Schnitger may indeed have significantly reduced his flueways for a more restrained power in smaller acoustics, much as we see in the data for D. A. Flentrop’s organ, but this is speculation without data on unmolested pipes. The Steinkirchen organ is reportedly the least tonally modified of Schnitger’s organs, but Rudolf von Beckerath’s documentation of that organ lamentably omits the crucial toe diameters and flueway depths.³⁰

Perhaps of more interest, Schnitger’s Germanic voicing is not considered vocale by some American organ builders who practice that style; it is considered an instrumental style with brighter harmonic richness more like that of D. A. Flentrop. The vocale voicing I have observed trends to more open toes, more closed flueways in modern work (and very deeply open flueways in some ancient examples), varying degrees of languid counterbevels, and very high cutups in both older and modern work. Vocale cutups tread in that range of timbres between a principal and a brighter flute.31 Subjective impressions suggest that vocale voicing cuts the vortex above the height where it spins at the frequency of the tuned resonator, i.e., above the point where Coltman’s impedances match and Ising’s fundamental forms most quickly at I = 2. This is a very rough model for vocale voicing, but voicing data are virtually non-existent for pre-Schnitger vocale archetypes or their modern American practitioners. A recent YouTube video featuring George Taylor and John Boody contains an excellent discussion of vocale cutups: https://www.youtube.com/watch?v=_NT65GJNBrU.

American classically inspired voicing has evolved. In their description of their lovely Opus 24 in The Diapason, Richards, Fowkes & Co. stated that “voicing our pipes a little slower relaxes the speech and helps them blend better.”³² “Slower voicing” does not mean that a pipe’s speech is slow to form, it means quite the opposite. With slower voicing the speech is slower to overblow to the octave when blown on higher pressure, and in that condition Ising has shown that the fundamental forms more quickly. To obtain this condition we raise the cutups and/or the languids. (Harmonic flutes will more easily overblow to their octave with languids set very low.) Gottfried Silbermann built very fast speech and “slower voicing” into his pipes with his extended upper lip, extremely high languids, and generous cutups. The blend of a Silbermann chorus is exceptional.

Bruce Shull has worked with John Brombaugh, Taylor & Boody, and Paul Fritts & Co. He has recently written a very informative article on the tonal qualities of sand-cast pipe metal. When voicing pipes made with this metal,

. . . [they] behave the best when they are rather open at their wind[flue]ways. . . . A counter bevel on the front edge of the languids is quite frequently found in antique pipework; today this can be achieved simply by abrading the front edge of the languid with a simple brass file with cross hatching scribed into one surface. The inside edge of the lower lip should remain smooth and must have a burr-free inside edge. . . . It may be that voicing styles that utilize nicking of the languid front edge will produce tonal results that are not very different between sand-cast and stone-cast pipe metal. . . . The organs [voiced with these pipes] have a solid and full sound with a very sweet character at the same time. There is a hint of breath in the sound due to the open windways and abraded languid fronts but the speech is immediate and yet gentle, and the blend is superb. The speech is such that the voicers find themselves doing less “fussing” with the pipes, and, in fact, the pipes have taken much less time to finish on site.³³

Although Silbermann’s resonators had thin and very stiff walls of about 90% hammered tin, he would no doubt agree with these voicing comments.

The power of inductive logic

The sound of a pipe organ can spark strong emotions, and the subject of voicing can spark fierce emotional debate. Voicing is indeed complex. We could spend a lifetime exploring its wonderful variety, but with some effort it is comprehensible.

This brings us full circle to the leading quote in this article: “Inductive logic is much more difficult­—but can produce new truths.” Inductive logic requires data, and the collection of data and its analysis requires effort. Some may find the effort required by inductive logic inconvenient if they accept the idea that all opinions have equal value, an extraordinary belief that curiously took root in American public education in the 1970s. But we have known since the time of Francis Bacon’s formalization of the scientific method that Nature yields only to data and cares nothing about our opinions. The inductive models in this article represent a significant effort to understand the data, and as new data emerges these models will no doubt be refined or replaced by others with better models. This is the power of inductive logic.

Silbermann’s inductive brilliance

The organs built at Freiberg in 1714 and much later at Großhartmannsdorf in 1741 are voiced on similar wind pressures. The regularity and similarity of the toes and flueways in these two organs establish that Silbermann devised successful models of voicing at the beginning of his career. Many organbuilders experiment with these complex variables to improve their sound over the course of their careers. Data previously published in The Diapason suggest that Silbermann’s regularity is probably unique among organbuilders. Figure 21, for example, shows that the Hooks treated toe constants as a completely free variable.³⁴ The regularity of Silbermann’s work may imply a limited tonal palette, but his youthful brilliance in finding a set of scaling and voicing models that would work in a wide range of acoustics and wind pressures is simply astounding. 

Silbermann’s data reveal an intellect that embraced inductive models. These models are not recipes from received wisdom. They are unique to Silbermann, and they exhibit the traits of inductive logic based on experimental data. Consider for a moment that Silbermann, the son of a carpenter, was not likely given a formal education in mathematics and science; this was the province of the wealthy and political elite during the time of Silbermann’s youth. Greß’s data and their implied theoretical models of voicing clearly represent an intellectual tour de force. Silbermann’s sound is indeed controversial, but Silbermann’s insights can teach us a great deal about the theoretical foundations of tonal design and voicing.

Organ literature often waxes nostalgic about the “secrets” of the old masters. The secret to their success was just the hard work of analyzing the problems they faced. Whether we are looking at the balanced ratios of the Isnards, the carefully calculated toes and flueways of Silbermann, or the Romantic sounds of Cavaillé-Coll, we see the work of analytical minds in the pursuit of artistic beauty. It may come as a surprise to know that Cavaillé-Coll and John Brombaugh were both trained as engineers. There is no gulf between art and science; they are mutually bound.

Silbermann’s unique sound

Gottfried Silbermann’s sound does not follow classical North German or French models. A typical North German chorus has a restrained power from its more closed flueways, a chorus fire supplied by its mixtures, and a strong fundamental supplied by the very wide, leathered shallots of its chorus reeds. A Classical French chorus has a restrained power from its more closed toes and a chorus fire supplied by its reeds. Silbermann combines powerful French reed fire with a powerful flue chorus derived from deep flueways, more open toes, and the widest possible mouths. Gottfried Silbermann’s sound is not a synthesis of classical French and North German organs, it is unique, and its blend and clarity make the sound of Bach come alive. Follow this YouTube link to the carefully restored Silbermann at Lebusa: https://www.youtube.com/watch?v=oOoSkB2UVMw.³⁵ The temperament is a form of meantone devised by F.-H. Greß.³⁶

Meantone

Gottfried Silbermann’s voicing and blend work very well in meantone. With the exception of “big city” organs such as the Frauenkirche organ in Dresden, Silbermann maintained the use of a very mild 1⁄6-comma meantone even when confronted with strong opposition from Johann Sebastian Bach. There is no dispute that equal temperament is essential to a vast range of wonderful literature, but we have also come to understand that meantone has a tonal beauty and gravity sorely lacking in equal temperament. This was a concept well understood by Bédos, who abhorred equal temperament.³⁷ Meantone was perhaps a part of Silbermann’s French legacy. 

Very few of Silbermann’s organs have survived in any form of meantone, but the lovely organ in the Freiberg Dom had organists who mostly succeeded in protecting it from the good intentions of its restorers. Here is a soundclip of the end of Bach’s Passacaglia and Fugue in C Minor, BWV 582, written in Bach’s early years, and played on the Freiberg Dom organ in 1980 in an approximation of its original meantone. The Picardy shift to C major at the end of the fugue resolves in a radiant third. This is Gottfried Silbermann’s sound. <soundclip 5>

Uncredited images reside in the collection of the author. Fr. Thomas Carroll, S.J., graciously suggested clarifications in the prose of this article.

Notes

21. Robert A. Heinlein, The Notebooks of Lazarus Long (New York: G. P. Putnam’s Sons, 1973). 

22. In 1972 I asked Dirk Flentrop for permission to measure his pipework and organs, which he graciously gave, adding that imitation was the finest form of flattery. Flentrop went on to predict that I would use my observations of his work to find my own sound (“Your ears will be different than mine”). He was a generous teacher, and secure in his knowledge. The Flentrop data shown in Figures 14, 16, 19, and 20 were taken in 1978 with the kind permission of David Rothe. The Hook data were taken in 2000 with the kind permission of Fr. Thomas Carroll, S.J. The Isnard data can be found in the original source in Note 26 and fully graphed in the source in Note 23.

23. Michael McNeil, The Sound of Pipe Organs, CC&A, 2014, Amazon.com. The toe constant equation: diameter of the toe = √ (toe constant*4*mouth width fraction*pipe diameter).

24. Heimo Reinitzer, Die Arp Schnitger-Orgel der Hauptkirche St. Jacobi in Hamburg, 1995. This is one of only three publications known to the author to include complete data for understanding the sound of an organ, i.e., its pipework, windchests, wind system, temperament, action, and layout. The other examples can be found in the author’s “The 1755 John Snetzler Organ, Clare College, Cambridge, restored by William Drake, Ltd., Joost de Boer, Director,” The Diapason, September 2019, pages 17–21, and “The 1864 William A. Johnson Opus 161, Piru Community United Methodist Church, Piru, California,” The Diapason, August 2018, pages 16–20, September 2018, pages 20–25, October 2018, pages 26–28, and November 2018, pages 20–24. I use Jahnn’s data for the Hauptwerk 16′ Principal on page 117 for Schnitger’s voicing; located in the façade, these pipes may have been the least accessible to changes in voicing. The restorer, Jürgen Ahrend, states on page 252 that the cutup, flueway, and toe hole data in this book were taken after his voicing (“. . . nach meiner Intonation”). Ahrend had to deal with previous interventions, and the current sound reflects his voicing. The toe data of the 16′ Principal taken after the restoration show extremely wide variations and some excessively open toes; Jahnn brilliantly solved this problem in 1925 by measuring the smallest diameters in the wind conduction between the windchests and the offset pipe feet—these are the values shown in Figure 14.

25. The Sound of Pipe Organs, pages 64–80. 

26. Pierre Chéron and Yves Cabourdin, L’Orgue de Jean-Esprit et Joseph Isnard dans la Basilique de la Madeleine à Saint-Maximin, ARCAM, Nice, 1991. The Isnard Grand Orgue toe/flueway area ratios on page 166 are almost exactly 1 up to 1′ in pitch for the entire principal chorus including both mixtures. The 8′ Montre deviates because it was revoiced in 1885. See page 59 on “closed up flueways” and page 175 on languids, which have about 50-to-58-degree bevels and about 75-degree counterbevels that slope inwards (counterbevels are more commonly vertical). Per my on-site observations on June 24, 1995, the upper lips are aligned with the lower lips, and the languids are lower than Silbermann’s, where the top of the Isnard counterbevel is level with the top edge of the lower lip.

27. McNeil. The Sound of Pipe Organs, pages 177–182.

28. Pierre Chéron and Yves Cabourdin, L’Orgue de Jean-Esprit et Joseph Isnard dans la Basilique de la Madeleine à Saint-Maximin, pages 132–133.

29. McNeil, The Sound of Pipe Organs, page 94.

30. Richards, Fowkes, & Co. See richardsfowkes.com/5_technical/beckerath for the Schnitger data taken by Beckerath. 

31. Vocale voicing has affinities to smooth Romantic English voicing with its very high cutups. None of the English Romantic chorus stops are harmonically rich, but they are intense with deep flueways; brightness is built by adding the smoothly voiced sounds of higher pitched stops. Instrumental voicing features harmonic richness in the individual stops, and those harmonics, when carefully voiced, can create a chorus of rich harmonics; this is the sound of a D. A. Flentrop. This distinction is also applicable to a reed chorus. The broad, leathered shallots of English and German reeds add smooth fundamental power. The rich harmonics of Clicqout, Callinet, and Cavaillé-Coll chorus reeds create a scintillating chorus depth. Much voicing resides in the broad range between these styles.

32. Opus 24, “Cover Feature,” The Diapason, May 2021, pages 26–28.

33. Bruce Shull, “Casting Pipe Metal on Sand,” Vox Humana, April 25, 2021.

34. See the toes, flueways, and ratios for E. & G. G. Hook, J.-E. & J. Isnard, W. A. Johnson, and J. Snetzler in “1863 E. & G. G. Hook Opus 322, Church of the Immaculate Conception, Boston, Massachusetts,” Part 2, The Diapason, August 2017, pages 18–21, “The 1864 William A. Johnson Opus 161, Piru Community United Methodist Church, Piru, California,” Part 4, The Diapason, November 2018, pages 20–24, and “The 1755 John Snetzler Organ, Clare College, Cambridge, restored by William Drake, Ltd., Joost de Boer, Director,” The Diapason, September 2019, pages 17–21. With the sole exception of Gottfried Silbermann, these are free variables for all other builders known to the author.

35. J. S. Bach, Komm, Heiliger Geist, Herre Gott, BWV 651, Christopher Lichtenstein, organist.

36. Frank-Harald Greß, Die Orgeln Gottfried Silbermanns (Dresden: Sandstein Verlag, 2007), pages 72–73.

37. Michael McNeil, “The elusive and sonorous meantone of Dom Bédos,” The Diapason, September 2020, pages 14–17.

Soundclips

4. [00:33] Louis Marchand, Tibi omnes angeli, Jean-Esprit Isnard, Couvent Royal de Saint-Maximin, 1774, Bernard Coudurier, BNL 112851 A, © SCAM/BNL 1995.

5. [00:55] Johann Sebastian Bach, Passacaglia and Fugue in C Minor, BWV 582, Gottfried Silbermann, Freiberg Dom, 1714, Karl Richter, Archiv 2533 441, © Siegfried Schmalzriedt, 1980.

Gerhard Grenzing

Born in Insterburg, Germany, Gerhard Grenzing trained in organbuilding with Rudolf von Beckerath in Hamburg, and gained further qualification by working with several other European workshops, mainly in Austria and Switzerland.

Beginning in 1967, he restored several organs in Majorca. In 1972, he set up his own workshop in El Papiol, near Barcelona, Spain. Approximately 250 new and restored organs have left the Grenzing workshop for Spain, France, Germany, Portugal, Belgium, Switzerland, Austria, Denmark, Italy, Sweden, Japan, South Korea, Bogotá, Brazil, Uruguay, Mexico, and Russia.

Since its founding in 1975 Radio France has remained the sole public radio broadcaster in France. The sprawling premises in the 16th arrondissement, occupied by the station from its inception, have been enhanced by a new 1,461-seat concert hall. However, in the design by the Parisian architectural bureau AS Architecture-Studio with acoustic consulting by the renowned firm of Nagata Acoustics from Japan, no organ was foreseen at the outset.

Only with a spirited campaign by dozens of leading figures in organ circles and the music world at large did the authorities eventually become convinced that in an organ city the likes of Paris and in a room like this one, a one-of-a-kind concert-hall organ must not be lacking. The attention that was aroused in this way spurred Radio France to have the organ project overseen by a committee of six organists, made up of Michel Bouvard, Thierry Escaich, François Espinasse, Bernard Foccroulle, Olivier Latry, and Jean-Pierre Leguay.

Once our firm had been awarded the contract for building the organ, and subsequent to an international call for tenders, we were actively supported and stimulated by the committee during the total of six years that the design phase, execution, and finishing were to last. The intense dialogue that came about among us as organbuilders and these experienced specialists was extraordinarily enriching and has already become a significant basis for future offshoot projects.

When I began to build organs in Barcelona, Spain, in the 1970s my work was quickly noticed in France and acknowledged with important contracts there. The company leadership in the Grenzing firm has meanwhile been transferred to my daughter Natalie Grenzing, seconded by the German master-organbuilder Andreas Fuchs. My sixty years’ knowledge is always appreciated. Our particular responsibility for the realization of the Radio France concert hall organ was shared by our entire team, consisting of twenty seasoned collaborators from seven nations.

Hallmarks of an organ for a concert venue

How, then, does a concert hall organ differ from its sibling in a church? It needs to feature a formal and coloristic relationship to all the tone colors of our instrumental and vocal musical culture. From a wafting pianissimo to the most massive fortissimo it should accompany, enhance, and provide the foundation for soloists, choirs, a chamber orchestra, and the large symphony orchestra. It should be capable of fulfilling its role in the orchestral literature and serve in the various styles of organ repertory. Finally, composers and improvisers should construe such an organ as an inspiring and subtly appointed medium for new works.

In May 2010, following the awarding of the contract, a meeting was held with the committee, in which, with the participation of six collaborators from our team, the technical and especially the tonal conceptions as well as the design of the consoles and accessories were discussed and voted on. It was only in this meeting that, through creative interplay among all those participating, the definitive specification and the technical details of the organ were determined; some among them were decidedly innovative. Several registers are located on an auxiliary windchest, so that they can be used in the Grand-Orgue as well as in the Pedal.

In many aspects of designing this organ we broke new ground tonally and technically. To our knowledge, for example, there exists no other instrument that may be played simultaneously from an electric console with proportional action and from a mechanical console. Our idea of a three-rank Gamba chorus with 4′ extension was accepted. For this we envisioned a bright tone color, almost as a preliminary stage leading up to the use of high mutations or mixtures.

Our wish to have variety in the area of reeds was received favorably as well. Thus not only was a chamade instituted but also a high-pressure division with tubas, which—enhanced by high-pressure flutes—sets the instrument off against the orchestra or, with its “broad shoulders,” underpins the same. Similarly, the Cor anglais in the Solo division, for example, was developed with a particular color for solo work.

We understand that French ears have a predilection for the sound of the indigenous French reed stops. As a result of our studies we are constantly aware in what country and for what ears we are creating (or, even more important, restoring) sounds. Hence a careful distinction was made between reed stops in the German style—which, versatile in their combination possibilities and together with the flues yielding various vowel sounds, can be used polyphonically—and the reed stops usual in French organs. The names of these stops make them recognizable by the wording, such as Trompete as opposed to Trompette.

The organ casework was designed by the architect of the hall, taking our technical/stylistic specifications into account. The instrument is thus so integrated into the hall that it comes across not so much as a distinct body but above all by virtue of the huge, 12 meter by 12 meter organ façade.

Our technical designer succeeded in fitting the eighty-seven registers with their 5,230 pipes into a depth of only some 3.84 meters, yet with a sense of order and clarity. In the foremost row of the façade stand the 8′ and 4′ pipes of the Grand-Orgue and Pedal, then just behind them the corresponding 16′ pipes, which fill up the entire space of the central case image.

The austere basic outline is relieved by the array of pipe ranks in a free play of pipe sizes and foot lengths. The swell shades framing the façade symbolize in three levels the enclosed divisions of the first, third, and fourth manuals, which opens up on a glimpse of the pipes standing behind. The effect, further enhanced by lighting setups, lends a dynamic visual dimension to the organist’s playing. This lighting function may of course be turned off.

The case pipes, in typical Spanish fashion, are polished with a scraper applied perpendicular to the pipe body. Together with the multi-faceted artificial illumination an enlivening effect of subtle contrast with the pipe bodies is achieved, which in neutral light is transformed into a gossamer sheen.

The main façade is formed by pipes. Next to it are found the visible swell shades, and to the outside on either side the pedal, which is masked by acoustically transparent fabric.

The console arrangements

The mechanical-action attached console features a visual link to the conductor via a screen and a mirror. Both can be slid into the case. Special functions of the console include:

• four adjustable crescendos that may be assigned to any of the swell pedals;

• a cumulative device for all enclosed divisions (“All Swells”);

• for the manual couplers, mechanical or electric action may be selected;

• a MIDI replay and tuning system;

• freely adjustable interval couplers (prepared for; you can chose any interval—for example a third, fifth, ninth, or any other “strange” interval—for coupling to any manual and thus enrich the color of registration);

• freely adjustable divided pedal couplers (prepared for).

The mobile console on the orchestra plateau is equipped with proportional electric action (sensitive touch).

A tracker organ with refined touch-sensitive action enables the organist to control the crucial attack and release parameters of the pipe speech, the only way the potential for musical expressivity can be realized by means of the corresponding reaction of the wind. With a normal electric action this is not possible, since only an on/off contact is involved. On the other hand, proportional electric action accurately conveys the movement of the fingers to the pallets in the windchest. Even a pedal tone, which the organist has such a hard time controlling at a large instrument, can henceforth be given a surprisingly slow sound decay.

Particular features of the mobile console include:

• transparent design, with no pedestal of its own, thereby being extremely low-lying and easily movable;

• all divisions can be assigned to various keyboards, meaning an inversion between Grand-Orgue/Positif and Récit/Solo, e.g., Grand-Orgue on the first manual, the Positif on the second or vice-versa;

• the “point of contact,” that is the exact place within the keydrop at which the note sounds or cuts off, can be adjusted;

• the lateral position of the pedalboard can be variously adjusted, for example C2 under manual C3 or D2 under manual C3.

Features common to both consoles:

• both consoles have four 61-note manual keyboards that are capped with bone and ebony. The pedalboards with 32 keys are made of oak. Via the touchscreen the organist can store personal files or, for example, adjust the speed of the tremolos;

• the key sostenuto functions either as an addition (that is, all depressed keys continue to sound) or as a substitution (the previously depressed keys are cancelled when new keys are depressed). When one of the two functions is activated, it is cancelled by activation of the other function;

• both consoles can be played simultaneously. Priority for the respective registration can be assigned at will to the mechanical or to the electric console.

Further particularities:

• there is a sequencer with wireless remote control for the assistant, so that the organist is not inconvenienced;

• USB memory sticks can be used for personal data;

• via a decimal keyboard (like a telephone keyboard) and a touchscreen the combination action in its versatile modes of utilization is memorized. Thousands of combinations can be called forth. Various combinations and levels are accessible only by means of a code. Organists can rest assured that they will truly have their combinations available to them.

Tonal considerations

We exchanged views extensively with composers, conductors, and organists (especially with organist-conductors) over tonal conceptions and once again express our thanks for the patient exchange of debate on this important subject. Often the remark was made that conductors ask organists to reduce the registration more and more, as the organ is one way or another too intrusive. We believe that this intrusiveness may be attributed in the pianissimo realm to the attack, the transient speech process (Einschwingvorgang) of each pipe, and in the forte realm mainly to the “organ-typical strident” tone of the mixtures, being too set apart from the tone color of the orchestra.

For a long time now we have felt confident in having recognized the solution in the most thoroughly refined attack behavior of each pipe. Despite its initial emission, at once quick and gentle, each tone should develop freely and in an unforced way. Thereby a certain “merging” into the sound of the orchestra can be furthered. Olivier Latry expressed the same idea in the symposium (see Appendix: A symposium on the concert hall organ).

Typical organ tone is to a very significant extent produced by mixtures and their quint ranks. For this reason we set the unison ranks in the Grand-Orgue mixture apart. The quints are then available via a separate register.

As a contrasting function there is in the Grand-Orgue a Cymbal with freely adjustable intervals. The sound can thereby be registered in the most varied colors as well as in the manner of actual Cymbals, but particularly as Ninths and Septièmes, whereby the organ, even in the midst of a triple forte in the orchestra, remains audibly distinct.

The instrument is divided into seven tonal groups in all that can either correspond with each other or be set off soloistically: Grand-orgue, Récit expressif, Positif expressif, Solo expressif, Solo Haute Pression [high-pressure] expressif, Chamade, and Pedal.

As an unusual tonal effect, in the Positif a wind pressure is available that is progressively modifiable by means of a separate swell pedal. As opposed to the standard wind cutoff this has the advantage that the manipulated pipe tone of all stops in this division remains less out-of-tune and better supplied, as not the quantity but only the pressure of the wind flow is changed.

From November 7 to 9, 2013, there was an initial, in-depth examination by the commission of the almost fully set up organ in our generously proportioned erecting room. For the first time in the large room with its 17 meters height and acoustics acclaimed for their high quality, the experts were able to play the instrument, exploring its features and discussing it with us. It thus seemed appropriate to organize the first concerts on the next day, followed by a symposium entitled “Organs in Concert Halls.” The members of the commission offered the concert, allowing as well the possibility of a discussion among some eighty specialists we had invited from throughout Europe (see https://www.youtube.com/watch?v=Xw1D5i_luFA; www.youtube.com/watch?v=YtagKK0VALo; and the summary of the discussion in the appendix).

Installation of the organ in Paris and its tonal characteristics

Following erection of the organ and the first on-site tests, the instrument was optimally adjusted to the room. We were eager, as a challenge from the outset, to take on the dauntingly dry acoustic of the hall. Once again, the instrument had to be adjusted to the tonal power of the orchestra, without relinquishing the tonal poetry and subtleties of the various colors and dynamic levels. We were most grateful indeed for the close collaboration and numerous instructive and supportive moments spent with the organists of the commission, in particular Olivier Latry.

From May 7 to 9, 2016, Radio France hosted dedication concerts with fifteen organists whose programs ranged from family concerts, a “Poetry and Organ” program, and one of improvised Andalusian-Arab music, to the avant-garde. The performers were Pascale Rouet, Coralie Amedjkane, David Cassan, Guillaume Nussbaum, Freddy Eichelberger, Juan de la Rubia, Lionel Avot, and Els Biesemans. The crowning final concert featured organists Michel Bouvard, Thierry Escaich, François Espinasse, Olivier Latry, Shin-Young Lee, and Jean-Pierre Leguay on May 9. You can hear the program on the internet at https://www.youtube.com/user/GerhardGrenzing.

Radio France intends to put the newly created instrument to use in highly multifarious ways. A campaign has been undertaken for the founding of a circle of patrons and donors committed to future activities focusing on this organ. The idea has been broached for workshops and study trips, public masterclasses, promotion of young titular organists, organ and cinema, a cycle of radio plays with France Culture, as well as a composition contest. Since Radio France records all its concerts, thorough maintenance of our instrument is important: it is carried out by our Parisian colleague Michel Goussu.

My heartfelt thanks for the confidence and the patient, consistently professional collaboration goes out to the six organists of the Radio France organ commission, the construction director Nadim Callabe, the conservator (or curator) of the organ Jean-Michel Mainguy, and most particularly the twenty collaborators on my staff.

I have in gratitude dedicated the success of the project to my master teacher Rudolf von Beckerath, who came as an apprentice to Paris and went away seven years later with knowledge to impart, and to our collaborator and friend Andreas Mühlhoff, who departed from us in sorrowful circumstances.

Perspectives

Following completion of the instrument one is beset with many thoughts: wherefore this effort? In the course of the last turn of the century the question was often asked: What will become of the organ in the future? Aware that the organ is the most evolution-prone of instruments, one could answer the question about its future development that the organ adapts to the needs and the spirit of the society of its time. Or, better put, it expresses it as a kind of mirror. But what is indeed our Zeitgeist of today?

Perhaps this: more and more we are determined by today’s technology. Our entire doings must occur ever faster. We want to have everything that can possibly be had. Even acknowledging that what seems modern today will already be outdated the day after tomorrow, we cannot simply exit this cycle. As was remarked at the end of the symposium, it seems to me that observance of musical ethics provides guidance in value boundaries.

In our shop we give full rein to the most novel technical developments and further enhance them. We are nevertheless very careful not to let ourselves be distracted, cultivating or incorporating noble, time-tested musical values.

Appendix: A symposium on the concert hall organ

We value any opportunity for enhancing the exchange of ideas. The Barcelona airport is located only twenty-five minutes away from our shop. Our slogan, “We are not far away, but rather neighbors,” was once again confirmed. On November 8, 2013, a symposium on concert hall organs was held in our shop. The impetus came from the new organ for Radio France, which at that time was nearly completed and set up in the shop. Thanks to the spontaneous initiative of our collaborators, the space occupied by our restoration division was converted into a standing buffet restaurant. The symposium was followed by two further days with public children’s concerts, a jam session, and a concluding silent film with Juan de la Rubia as improvising organist.

Summary of the symposium on November 8, 2013, in El Papiol

Bernard Foccroulle opened the symposium and noted the lack of organs in concert halls in France. The new instrument should serve the needs of Radio France and the two orchestras that perform there.

Olivier Latry expressed his regret that, for the most part, organs in concert halls do not live up to the expectations of musicians, orchestras, and conductors. The reason: the organs are often designed in the style of a special era or in the particular style of a given organbuilder. An example thereof is the wonderful organ in Taiwan with its sixty stops. Playing it requires two assistants, and very little literature is playable on the tracker instrument.

An instrument of lesser beauty will seldom be played. A few organs have been restored and brought up to date (for example, the Gewandhaus in Leipzig), and are played thirty-five to forty times each year.

In the Radio France complex an all-encompassing project needed to take in not only the organ but also the hall, the construction in general, and the acoustics. An organ cannot sound good in just any acoustic. Hence the need for the collaboration of an acoustician.

What are the particularities of a concert hall organ? Conductors often blame the organ either for being too loud (thereby overpowering the orchestra) or too soft (thus being covered up by the orchestra). The organ must possess a wide dynamic range. The multiplicity of sounds and transient attack parameters of the orchestral instruments bring about synchronization problems with the organ. Hence the necessity of a sound with cautious attack that can thereby come about with a kind of inertia. The sound of the organ must be capable of entering more or less slowly. The Radio France instrument meets this criterion; to this are added dynamic enclosed divisions, mechanical action, as well as the proportional electric action.

Olivier Latry emphasized that the collaboration of all the organists involved in the project was highly useful. Michel Bouvard noted that the comprehension of the various authorities at Radio France made it possible to enlarge the specification, such that the organ can serve not only as an organ for orchestra (and accompaniment for choir and children’s choir), but also as a solo instrument.

Gerhard Grenzing explained that the new organ is not an orchestral organ but should be an organ for the orchestra. This implies a refined voicing style and individually cultivated attack of each pipe. He emphasized the dynamics of the swell boxes, of the very soft stops for the accompaniment of the room-filling soloists, and of the very loud stops that—without succumbing to vulgarity—are meant to give the instrument “broad shoulders.” This makes it possible to respond to the orchestra without lording over it.

This is the result of many considerations shared among conductors and organists, for which Grenzing expressed his gratitude once again, as well as of the work of his team that contributed its sensitivity, perseverance, and soul to the cause, without which success would not have been possible.

Michel Bouvard shared his experience as director of the Toulouse les Orgues festival. In Toulouse a considerable richness in organs is available, but even if the ten best organists in the world had been invited that would not have been enough; in ten years the audience would have become weary of the same basic fare, and so numerous innovative programs and activities enriched the festival offerings. The high level of the concerts was maintained. Bouvard holds great hope for the same success at Radio France.

The organ must be brought “out of the chapel” in order to create momentum for a new public; a new place in music history must be found to lend it a new role of its own, and not only as a church instrument. It is important to gain a young audience through educational endeavors, for which models exist in the world, for example the Philharmonie in Budapest. Another possibility would be to organize “cinema concerts.”

Olivier Latry underscored Bouvard’s suggestion and reported on his experience in Manchester. There he was asked, as a prelude to Mahler’s Eighth Symphony, to improvise for twenty minutes on Veni Creator. To many who had never heard an organ, this came as a revelation.

François Espinasse suggested developing initiatives with schools and universities. In this way public relations work and scientific research would be brought together in fruitful collaboration.

It is also among the organist’s tasks to turn to composers, since the latter often seem to be wary of the instrument. It is to be hoped that the organ of Radio France will enable a dialogue with them.

Jean-Pierre Leguay recalled his experience with the composers of the 1960s and 1970s, which was a very good time for the development of contemporary music. It was discovered that the organ is an unbelievable generator of tone colors. However, for many organists, above all those who were not composers, the organ was “slumbering, back there in the organ loft, hidden away and dusty.”

Study of orchestration at the conservatory changed the composers’ way of hearing and revealed the organ’s countless possibilities for tone colors. Working together with composers is of crucial importance. It is important to show them that the organ is just as rich and expressively potent an instrument as others. A concert hall organ is ultimately an element of this musical laboratory, an opportunity for composers to expand their resources through experimentation. The public should not consider the organ as a purely liturgical instrument.

Michel Bouvard recalled an anecdote concerning Pierre Boulez. To the question of why he had not composed anything for the organ he answered: “The organ has no relation to my musical ideas, since it functions for large masses of sound such as crescendo-decrescendo, whereas I seek the gentle substance of a flute or an oboe.” (A symptomatic answer from the lips of such an eminent composer.)

Christian Dépange noted that this new organ that we are now getting to know must be a kind of combative element of conviction and pedagogy for the public.

Yves Rechsteiner, successor to Michel Bouvard with Toulouse les Orgues, asked, can the pipe organ open up musical aesthetics other than classical music? How does the role of the pipe organ stand up to that of the electronic organ, which offers a much broader variety of sounds?

Bernard Foccroulle noted two applications of technology: on one hand that of the image in the service of information and publicity that could be used to make the organ more accessible, more comprehensible, and on the other hand that of making modification of the sound possible, thereby producing new sounds. Foccroulle encouraged Olivier Latry to report on his experience in digital production and the relationship between synthesizer and organ. Latry told of his experiences in Hollywood with a system in which the synthesizer was a part of the organ, opening up many perspectives. Seen in this light, the question is perhaps the possibility of an eventual addition of such a system to this organ. “I’m thinking for example of the possibility to capture the tone of the organ with swell shades closed, then projecting it via loudspeakers into the room.” Gerhard Grenzing noted in conclusion, “In this race with technology that makes nearly everything possible, I would like to recall that the nature of the organ emerging out of inner necessity is the conveying of musical emotions based on acknowledgement of ethics.”

Documentation of the symposium may be reviewed on the internet at: http://grenzing.com/RadioFrance/.

This article is a free translation by Kurt Lueders of Gerhard Grenzing’s updated text in German, used with kind permission of the original publisher, the review Ars Organi.

Builder’s website: www.grenzing.com

Radio France website: www.radiofrance.fr

Listen to the organ here: https://www.youtube.com/watch?v=nR0gTDZmRR8

 

2016 Gerhard Grenzing organ

GRAND-ORGUE

16′ Montre (61 pipes)

16′ Bourdon (61 pipes)

8′ Montre (61 pipes)

8′ Suavial (61 pipes)

8′ Flûte harmonique (12 basses from Bourdon, 49 pipes)

8′ Bourdon à cheminée (61 pipes)

51⁄3′ Grosse Quinte (61 pipes)

4′ Prestant (61 pipes)

4′ Flûte conique (61 pipes)

31⁄5′ Grosse Tierce (61 pipes)

22⁄3′ Quinte (61 pipes)

2′ Doublette (61 pipes)

II Sesquialtera (122 pipes)

II–V Grand Cornet (305 pipes)

III–IV [Mixtur] Octaves (207 pipes)

II–III [Mixtur] Quintes (183 pipes)

III–IV Cymbal (220 pipes)

16′ Trompete (61 pipes)

8′ Trompete (61 pipes)

Positif Expressif

16′ Quintaton (61 pipes)

8′ Principal (61 pipes)

8′ Salicional (61 pipes)

8′ Meditation (TC, celeste, 49 pipes)

8′ Bourdon (61 pipes)

4′ Prestant (61 pipes)

4′ Flûte douce (61 pipes)

22⁄3′ Nasard (61 pipes)

2′ Doublette (61 pipes)

13⁄5′ Tierce (61 pipes)

11⁄3′ Larigot (61 pipes)

11⁄7′ Septime (61 pipes)

1′ Sifflet (61 pipes)

IV Mixture (244 pipes)

16′ Basson (61 pipes)

8′ Trompette (61 pipes)

8′ Clarinette (61 pipes)

Tremblant

Récit Expressif

16′ Principal (6 basses fr Bdn, 54 pipes)

16′ Bourdon (61 pipes)

16′ Gambe (6 basses fr Bdn, 54 pipes)

8′ Principal (32 basses fr 16′ Principal, 29 pipes)

8′ Gambe (32 basses fr 16′ Gambe, 29 pipes)

8′ Voix céleste (TC, 49 pipes)

8′ Flûte harmonique (61 pipes)

8′ Cor de nuit (32 pipes fr 16′ Bourdon, 29 pipes)

4′ Octave (61 pipes)

4′ Flûte octaviante (61 pipes)

22⁄3′ Nazard (61 pipes)

2′ Octavin (61 pipes)

13⁄5′ Tierce (61 pipes)

IV Plein jeu (244 pipes)

16′ Bombarde (61 pipes)

8′ Trompette harmonique (61 pipes)

8′ Hautbois (61 pipes)

8′ Voix humaine (61 pipes)

4′ Clairon (61 pipes)

Tremblant

Solo Expressif

8′ Choeur de cordes (I–III, 147 pipes)

8′ Voix céleste (TC, 49 pipes)

8′ Flûte traversière (61 pipes)

4′ Choeur de cordes (ext 8′, 36 pipes)

4′ Flûte traversière (ext 8′, 12 pipes)

2′ Flûte (ext 8′, 12 pipes)

8′ Cor anglais (61 pipes)

Solo Haute Pression

8′ Flûte (61 pipes)

4′ Flûte (ext 8′, 12 pipes)

16′ Tuba (61 pipes)

8′ Tuba (ext 16′, 12 pipes)

4′ Tuba (ext 16′, 12 pipes)

Chamade

16′ Chamade (fr 8′)

8′ Chamade B (25 pipes)

8′ Chamade D (36 pipes)

Pédale

32′ Bourdon (ext 16′, 12 pipes)

16′ Principal (32 pipes)

16′ Soubasse (32 pipes)

16′ Contrebasse (32 pipes)

16′ Montre (G.-O.)

16′ Bourdon (Réc.)

102⁄3′ Quinte (32 pipes)

8′ Principal (ext 16′, 12 pipes)

8′ Bourdon (ext 16′, 12 pipes)

8′ Violoncelle (32 pipes)

8 Flûte (Solo)

62⁄5′ Tierce impériale (ext 31⁄5′, 12 pipes)

51⁄3′ Quinte (ext 102⁄3′, 12 pipes)

4′ Octave (32 pipes)

31⁄5′ Grosse Tierce (32 pipes)

32′ Posaune (32 pipes)

16′ Posaune (ext 32′, 12 pipes)

16′ Basson (32 pipes)

8′ Trompete (32 pipes)

8′ Basson (ext 16′, 12 pipes)

4′ Clairon (ext 8′, 12 pipes)

8′ Chamade (fr Chamade)

4′ Chamade (fr Chamade)

Couplers

G.-O–Ped.

Pos.–Ped.

Réc.–Ped.

Solo–Ped.

G.-O 4′–Ped.

Pos. 4′–Ped.

Réc. 4′–Ped.

Solo 4′–Ped.

 

G.-O. 16′–G.-O.

Pos. 16′–G.-O.

Pos.–G.-O.

Recit 16′–G.-O.

Récit–G.-O.

Solo 16′–G.-O.

Solo–G.-O.

Ped.–G.-O.

 

Pos. 16′–Pos.

Récit 16′–Pos.

Récit–Pos.

Solo–Pos.

 

Récit 16′–Récit

Solo–Récit

 

Tuba–G.-O.

Tuba–Pos.

Tuba–Récit

Tuba–Solo

Tuba–Pédale

 

Chamade–G.-O.

Chamade–Pos.

Chamade–Récit

Chamade–Solo

 

93 stops, 93 ranks, 5,308 pipes

Manual compass: 61 notes (C–C)

Pedal compass: 32 notes (C–G)

a1=442 Hz at 22 degress Celsius

Photo credit: Christophe Abramowitz.

Lorraine S. Brugh

Lorraine Brugh is professor of music and Kruse Organ Fellow at Valparaiso University, Valparaiso, Indiana. She recently served as director of the university’s study abroad program in Cambridge, England.

Saturday is market day in Alkmaar. On the way to the Sint-Laurenskerk from my hotel there were stalls filled with fresh fish, cheese, fruits and vegetables, breads and desserts. Tempting as they were, I hurried through to make the 9:00 a.m. starting time for the first round of the International Schnitger Organ Competition 2019. With the church bells chiming 9:00, the jury entered, and the members were introduced.

The jury

The five jury members for 2019 included: Martin Böcker, lecturer at the Hochschule für Musik und Theater Hamburg and artistic director of the Orgelakademie Stade, Germany; Bernard Foccroulle, professor of organ for the Conservatoire of Brussels, Belgium; Krzysztof Urbaniak, head of the organ and sacred music department, Bacewicz Academy of Music in Łódź, Poland; Bas de Vroome, organ professor at the Rotterdam Conservatorium voor Muziek, the Netherlands; and Wolfgang Zerer, professor of organ at the University of Music and Performing Arts in Hamburg, Germany. The competition began in 1991 and is held biennially in Alkmaar, centered at the Great Sint-Laurenskerk in the city center.

The organs

Great Sint-Laurenskerk houses two important organs. The instrument that has already won the grand prize, of course, is the large Germer Van Hagerbeer/Schnitger organ (1646/1725) at the west end, both a sight to behold and a delight to hear. Adding to its appeal is the controversy surrounding its history, which has only served to heighten its prominence. Arp Schnitger died before working on the instrument and his son, Frans Caspar Schnitger, finished the instrument.

The second and smaller instrument is in a swallow’s nest gallery on a side wall of the nave just east of the apse and was built by Jan Van Covelens in 1511. Meantone temperament tweaked this Western equal-temperament ear with unusual tonalities and pitches. Hearing the older music of Sweelinck, Frescobaldi, Hassler, and others offered a glimpse into the way this music originally sounded. The Van Covelens organ is the oldest playable instrument in the Netherlands.

The competition

Forty-five applicants from thirteen countries submitted an audio performance to be considered for the 2019 biennial competition. From those ten were chosen to compete in Alkmaar. To prepare for the competition and its organs, the ten finalists were all given a spring weekend in Alkmaar practicing on the instruments. This gave the competitors time to adjust to the mechanical demands of each instrument and their differences as well as conceive registrations before the competition week.

During the first round each contestant performed on both instruments. As we moved from the apse to the west end the performer also moved from the Van Covelens organ to the Schnitger. Pieter Van Dijk, city organist in Alkmaar, explained the differences of the two instruments from the performers’ point of view: the Van Covelens has a smaller manual compass, limited pedal range, and smaller keys and pedals than the Schnitger. The oldest stop, from 1511, is the Hoofdwerk 6′ Holpijp, which starts at low F. The Trompet in the Pedaal (this division’s only stop) balances perfectly with the 8′ Doof (Praestant) in the manual, though it sounds very loud from the console. The Borstwerk and the Hoofdwerk were both used with a 4′ stop as the foundation in one performer’s final Sweelinck variation. There are almost no repeats in the Mixtuur. The Scherp is intentionally weighted to give the top intensity, just as choirs are often weighted with more sound in the treble than in the bass registers.

The Schnitger organ fills the entire west end of the nave, a beautiful and massive case. In 1725 Schnitger added a 2′ flute in the Groot-Manuaal and the 2′ Nachthorn in the Pedaal, adding a brighter and singing quality to the instrument. Schnitger added these at his own expense as he felt the organ was incomplete without them.

A large part of the competition’s challenge lies in transitioning from one instrument to the other in the space of a few minutes. The pieces in this round were all compulsory: Sweelinck, Erbarm dich mein, O Herre Gott, SwWV 30, on the Van Covelens organ, and Bach, Allein Gott in der Höh sei Ehr, BWV 664, and Prelude and Fugue in C Major, BWV 547, on the Schnitger.

There was no memorization requirement for the competition, and competitors were known to the jury and audience only by their contestant number. So, while the playing level was generally strong, musically and technically, there was no way to know who was playing during their performance. Listening became an exercise in hearing subtle differences between interpretations of a piece, considering various tempi, and listening to how performers used the room and its acoustics.

Following the ten performances, the six finalists to advance to the second round were Victor Manuel Baena de la Torre (Spain), Oliver Brett (United Kingdom), Freddie James (United Kingdom), António Pedrosa (Portugal), Daniel Seeger (Germany), and Vittorio Vanini (Italy).

The next round offered some choice in literature, this time played on the Kapelkerk organ in Alkmaar. The organ is a Christian Müller instrument from 1762, maintained by Flentrop since 1939 and restored by the firm between 1982 and 1986. The repertoire included a Buxtehude canzona of the player’s choice, three chorale preludes for manuals alone from J. S. Bach’s Clavierübung III (Wir glauben all in einen Gott, BWV 681, Allein Gott in der Höh sei Ehr, BWV 677, and Die sind die heilgen zehn Gebot, BWV 679), and a Bach toccata for manuals alone (BWV 910–916). A hot summer evening did not make playing these delicate pieces any easier. The jury selected Victor Baena de la Torre, Freddie James, and Vittoria Vanini as the three finalists for 2019.

The finalists

Victor Baena de la Torre (Spain, b. 1995): At the age of twelve de la Torre started playing guitar and piano and later studied these instruments at the Conservatory of Madrid. There he became interested in the interpretation of early music, especially for organ and harpsichord, and decided to study organ with Anselmo Serna and harpsichord and basso continuo with Denise De La-Herrán. As a basso continuo player, he has participated in various opera productions. He has participated in masterclasses for organ and harpsichord with, among others, Lorenzo Ghielmi and Bernard Foccroulle. He currently studies at the Conservatory of Amsterdam with Pieter van Dijk and Matthias Havinga.

Freddie James (United Kingdom, b. 1990): James started as a chorister at Southwark Cathedral, and after leaving the choir, he held positions as organ scholar at Croydon Minster and assistant organist at Sint-Nicolaas Basilica, Amsterdam. He was then organ scholar at St John’s College, Cambridge. With the choir, he performed in a range of venues around the world, including in Japan (Suntory Hall, Tokyo, Tokyo Opera City), the United States, Germany, the Netherlands, and Denmark, and on a number of radio broadcasts, including a recording for Chandos of works by Thomas Tomkins. He was subsequently organist of the Christuskirche, Stuttgart, and is currently organist of the Church of St. Peter and Paul, Oberwil, in Basel, Switzerland.

Vittorio Vanini (Italy, b. 1996): Vanini entered the Conservatorio of Como, Italy, in 2011, where he studied first with Luca Bassetto, then with Enrico Viccardi. In 2017 he completed a bachelor’s degree in organ with honor. During his studies he focused on organ literature, harpsichord, and thorough-bass with Davide Pozzi and on composition with Antonio Eros Negri and Caterina Calderoni. He is currently studying at the Schola Cantorum Basiliensis, Switzerland, in the class of Tobias Lindner. He has been working as a church organist in the parishes of Lurago Marinone and Cucciago, Italy, and he has given concerts in Italy, Germany, and Switzerland.

The final round

The final round returned to Sint-Laurenkerk with literature for both organs. For the Van Covelens organ, each contestant chose a song variation set by Sweelinck. On the Schnitger organ each finalist chose a large Bach chorale prelude from Clavierübung III or from 18 Choräle verschiedener Art and a prelude and fugue [BWV 532, 541, 546, or 550], and a work by Piet Kee from Gedenck-Clanck ’76.

The winners and prizes

The prizes reflect both the civic and religious relationships of this festival to the city of Alkmaar. Following the final round the jury announced the prizes:

Schnitger prize (first prize, €5,000)—Victor Baena de la Torre

The first prize of the competition is named after organbuilder Frans Caspar Schnitger (1693–1729), son of the legendary Arp Schnitger. In 1723–1725, at the instigation of the newly appointed city organist Gerhardus Havingha (1696–1753), Frans Caspar carried out the highly controversial renovation of the Van Hagerbeer organ in Alkmaar. Behind the unchanged organ cases, designed by architect Jacob van Campen, a completely new type of instrument in North German style arose for Holland. Schnitger thus achieved the definitive breakthrough of this aesthetic in Dutch organbuilding. The Alkmaar organ is the best-preserved instrument by him.

Flentrop prize (second prize, €2,500)—Vittorio Vanini

Flentrop Orgelbouw of Zaandam, the Netherlands, has executed many important organ restoration and new-build projects in the Netherlands and abroad, including the restoration of both organs in Grote Sint-Laurenskerk, Alkmaar. Flentrop Orgelbouw adopted the second prize of the International Schnitger Organ Competition during the tenure of Cees van Oostenbrugge, who was then the company’s director.

Third prize (€1,000)—Freddie James

Izaäk Kingma prize (audience prize)—Vittorio Vanini

Izaäk Kingma (1936–2004) was secretary of both Alkmaar organ foundations for many years: the International Schnitger Organ Competition Foundation and the Friends of the Organ Foundation. In addition to his career in education, he was active as an organist in various churches in Alkmaar, including the Trefpuntkerk and the Remonstrantse Kerk. Because of its great merits for the Alkmaar organ culture, the International Schnitger Organ Competition Foundation decided in 2004 to link its name to the public prize of the International Schnitger Organ Competition that takes place during the biennial Organ Festival Holland in Alkmaar.

The symposium

Running concurrently with the competition was an organ symposium, a series of workshops and masterclasses presented by the jury members. This year’s topic was “The better Schnitger?” The young organbuilder Frans Caspar Schnitger, son of the legendary Arp Schnitger, with his organ in Alkmaar, was the subject of the symposium. Workshops and masterclasses were offered for “accomplished amateur and professional organists.” Participants who wished to play for the masterclasses also prepared required pieces for the event.

The presentations included:

Martin Böcker: “Schnitger in Stade and Hamburg and what happens before and afterwards.” This presentation looked at the ways Arp Schnitger developed his premise for sound ideal and construction close to home before building instruments further afield;

Cees van der Poel: “The Zwolle Organ—Schnitger’s Ticket to Holland.” This commission began Arp Schnitger’s international career, opening the way to further projects in the Netherlands;

Krzysztof Urbaniak: “Activity of Schnitger’s pupils east of the Oder-Neisse line.” Dr. Urbaniak demonstrated the direct influence of the Schnitger style on Polish instruments through the students and apprentices of Arp Schnitger;

Gerben Gritter, professor of music theory and organbuilding at the Amsterdam University of the Arts. His doctoral thesis focused on the life and work of the organbuilder Christian Müller, the builder of the Sint-Bavokerk organ in Haarlem. He highlighted differences and similarities between Schnitger and Müller;

Frank van Wijk, organist at the Kapelkerk in Alkmaar: “The innovative properties that the Alkmaar organ still has to offer us today.” VanWijk described many of the events that keep the church and its organs in the center of the city’s life. Hosting children’s choir festivals, organ recitals, and other innovative programming keeps the community connected to this landmark church. The foundation that supports the festival brings guest performers and new music for these old organs in order to reach a new audience. Specific composition commissions and combinations of organ with choir, orchestra, or electronics are used to broaden the organ culture.

Concert and recital highlights

The festival included an organ and choral concert featuring the St. Salvator Chapel Choir, St. Andrew’s University, Edinburgh, Scotland, Claire Innes-Hopkins, director, and Bernard Foccroulle, organist. The Scottish choir delighted the audience with its sleek sound in a beautiful acoustic. The Schnitger organ created an interesting dialogue with its massive and varied sounds.

A noonday concert presented Cees van der Poel and Gerben Gritter playing works of Lübeck, Böhm, Jacob Wilhelm Lustig, and Johann Nikolaus Hanff on the Schnitger organ. A “Four hands and feet organ concert” put the spotlight on Pieter Van Dijk, city organist in Alkmaar, and Frank Van Wijk, playing solo and duet literature.

This is an ambitious festival, carried out by an army of volunteers. The festival committee created a hospitable welcome while running a well-planned, high-level event. Gratitude is due to all those who work hard to keep this instrument and its importance alive, giving pride of place to young organists ready to build their performance careers.