In the wind . . .

Valve jobs, ring jobs, and protection

Most faucets and spigots have rubber washers that act as gaskets. When you turn off a faucet, the washer is compressed, sealing the opening to the pipe and stopping the flow of water. If you turn faucets too hard when shutting off the water, you compress the washer more than necessary—not too big a deal, except the washer will squish and wear out more quickly.

The smooth operation of your automobile’s engine is all about controlling leaks. Piston rings, which are metal washers that seal the pistons against the cylinder walls, isolate the combustion chamber above the pistons from the lubrication of the piston rods and crankshaft. When the rings fail, the oil from below splashes up into the combustion, and now you’re “burning oil.” That’s what’s going on when excessive black and stinky smoke is coming out of your tailpipe. You need a ring job.

Above that combustion chamber are the valves that open to allow the air/fuel mixture from the carburetor or injector in to be ignited by the spark plug, and those that open to allow the exhaust to escape after the cylinder fires. (I know, I know, you diesel guys are waving your arms in the air, saying “OO, OO, OO . . . ” We’ll talk about diesel combustion another day.)

The valves are operated by the camshaft, which is also lubricated by the engine oil. If the valves leak, fuel and exhaust can trade places, and the engine’s operation gets screwed up. You need a valve job.

Perhaps you’ve had car trouble caused by a worn timing belt. That belt turns the camshaft at just the right ratio to the engine’s revolutions, so that intake valves open, letting in the fuel before the spark plug ignites it, and exhaust valves open after the firing, letting the exhaust out. My car’s engine has eight cylinders, and at highway speed, runs at about 2,500 revolutions per minute, which is 41.6 revolutions a second. All eight cylinders fire with each revolution, so there are 332.8 valve openings (and closings) each second. That’s cutting things pretty close. But we sure expect that engine to start every time, and to run like a clock hour after hour. Say you’re driving three and a half hours from New York to Boston. To get you there, you’re asking for 4,193,280 precisely timed valve repetitions. It’s a wonder it works at all.

It’s all about the holes.

I like to describe the art of organ building as knowing where to put the holes. Organbuilding workshops include immense collections of drill bits. My set of multi-spurs goes from half-inch to three-inches. They graduate in 64ths up to one inch, 32nds up to one-and-a-half, 16ths to two-and-a-half, and 8ths up to three inches. I have two sets of “numbered” bits (1-60 and 1-80), one of twist drills from 1/16 to one-inch, graduated by 64ths, and one set of “lettered” bits (A–Z).

If you’re interested in knowing more about those sets, follow this link: www.engineersedge.com/drill_sizes.html. You’ll find a chart that shows the numbered, lettered, and fractional sizes compared to ten-thousands of an inch: #80 is .0135″, #1 is .228″, just under ¼″ (which is .250). If you have all three sets, and mine are all packed in one big drill index, you’re covered up to nearly half an inch in tiny graduations. 

Why so fussy? Say you’re building tracker action parts, and you’re going to use #10 (B&S Gauge) phosphor bronze wire (.1018) as a common axle. You want the axle to be tight enough so there’s minimal slop (no one likes a rattly action), but loose enough for reliable free movement. A #38 drill bit is .1015 B&S Gauge—too tight by 3/1000s. Next one bigger is #37, .1040″. That’s a margin of 22/1000s, the closest I can get with my sets of bits.

And there are lots of holes.

Lots of the holes in our organs allow the passage of wind pressure. In the Pitman windchests found in most electro-pneumatic organs, there are toe-holes that the pipes sit on and rackboard holes that support them upright. There are holes that serve as seats for primary and secondary valves. There are channels bored in the walls of the chests to allow the exhausting of pouches and there are exhaust ports in the magnets. All of those holes, except in the rackboards, have valves pressed against them to stop the flow of air. 

Let’s take that a step further. A fifty-stop organ has over 3,000 pipes. That’s 3,000 pipe valves. If that organ has seven manual windchests (two in the Great, two in the Swell, two in the Choir, and one in the Solo), that’s 427 primary valves, 427 secondary valves, and 427 magnet exhaust ports, in addition to the pipe valves. There’s one Pitman chest in the Pedal (Spitz Flute 8′, Gedackt 8′, Chorale Bass 4′, Rauschpfeife III) with 32 of each. And there are three independent unit chests in the Pedal with 56 of each. Oh, wait. I forgot the stop actions, 50 times 3. And the expression motors, eight stages each, 16 times 3. And two tremolos . . . That’s 9,162 valves. Not counting the expressions and tremolos, every one of those valves can cause a cipher (when a stop action ciphers, you can’t turn the stop off). 

How many notes do you play on a Sunday morning? The Doxology has 32 four-part chords. That’s 128 notes. If you play it using 25 stops, that’s 3,200 notes, just for the Doxology! Are you playing that Widor Toccata for the postlude? There are 126 notes in the first measure. Using 25 stops? That’s 3,150 notes in the first measure! There are 61 measures. At 3,150 notes per measure, that’s 192,150 to finish the piece. (I haven’t counted the pedal part, and while the last three measures have big loud notes, there aren’t that many.) Using this math, you might be playing four or five hundred thousand notes in a busy service. And remember, in those Pitman chests, four valves operate for each note (magnet, primary, secondary, pipe valve), which means it takes 12,800 valve openings to play the Doxology, and 768,600 for the Widor. Let’s take a guess. With four hymns, some service music, an anthem or two, plus prelude and postlude, you might play 1,750,000 valves on a Sunday. (Lots more if your organ still has the original electro-pneumatic switching machines.) No ciphers today? Organ did pretty good. It’s a wonder it works at all.

Next time the personnel committee sits you down for a performance review, be sure to point out that you play 500,000 notes each Sunday morning.

Dust devils

Pull a couch away from the wall and you’ll find a herd of dust bunnies. Messy, but innocent enough, unless someone in your household is allergic to dust. But dust is a real enemy of the pipe organ. Fire is bad, water is bad, vandalism is bad, but dust is the evil lurker that attacks when you least expect it. A fleck of sawdust coming loose inside a windchest, left from when the organ was built, finds its way onto a pipe valve, and you’ve got a cipher.

Imagine this ordinary day in the life of a church. The organist is practicing, and the custodian is cleaning up in the basement. Airborne dust is sucked through the intake of the organ blower, and millions of potential cipher-causing particles waft through the wind ducts, through the reservoirs, and into the windchests, there to lurk until the last measure of the Processional March of the wedding of the daughter of the Chair of the Board of Trustees—whose family gave the money for the new organ. One pesky fleck hops onto the armature of the magnet of “D” (#39) of the Trompette-en-Chamade, and the last of Jeremiah’s notes continues into oblivion. (Ciphers never happen in the Aeoline when no one is around!)

I’m thinking about valves—how they work, what they do, what are their tolerances, and how many times they repeat to accomplish what we expect—because I was recently asked to provide an estimate for the cost of covering and protection of a large pipe organ during a massive renovation of the interior of a church building. There are organ cases on either side of the huge west window, and another big organ chamber in the front of the church, forming the corner between transept and chancel. There are lots of mixtures, and plenty of reeds—and with something like 3,500 pipes, a slew of valves.

The stained-glass west window will be removed for restoration, and the general contractor will construct a weather-tight box to close the hole. That’ll be quite a disturbance for the organ, with its Trompette-en-Chamade and mixture choruses. The plaster walls will be sanded and painted. The wooden ceiling with its complex system of trusses and beams will be cleaned and refinished. The entire nave, transept, and chancel will be filled with scaffolding, complete with a “full deck” 40 feet up, which will serve as a platform for all that work on the ceiling.

To properly protect a pipe organ against all that, removing the pipes, taping over the toeholes, and covering the windchests with hardboard and plastic is an important precaution. That means that all those little valves cannot be exposed to the dust and disturbance around the organ. To do that, you have to vacuum the chest surfaces, and organbuilders know how to do that without shoveling dust directly into the pipe holes.

The pipes that are enclosed in an expression chamber can be left in place if you disconnect the shutters, and seal the shutters closed with gaffer’s tape and plastic. Even, then, all the reeds should be removed, packed, and safely stored. 

The blower is the best way for foreign stuff to get inside the guts of the organ. It’s essential to prepare the organ blower for the building renovation. Wrap the blower’s air intake securely with plastic and heavy tape. Those 42-gallon “contractor” trash bags are great for this. And cut the power to the blower motor by closing circuit breakers, to be sure that it cannot be inadvertently started. Before you put the blower back into service, give the room a good cleaning, and allow a day or two for the dust to settle before you run the blower. It’s a simple precaution, but really important.

§

It’s a lot of work to do all this to a big pipe organ. And it’s a lot more work to put it all back together and tune it. For the same amount of money you could buy a brand-new Steinway Concert Grand piano if it’s a big organ. But if you fail to do this, the future reliability of the organ may be seriously compromised. 

A bit of dust gets into a toehole, and winds up sitting on the note valve. Even if the valve is held open a tiny slit, the resulting trickle of air is enough to make a pipe whimper. A fleck of dust gets caught in the armature of a magnet, and the note won’t stop sounding. And I’m telling you, you wouldn’t believe how tiny, almost invisible a fleck is enough to do that. Lots of organ reed pipes, especially trumpets, are shaped like funnels, and they aggressively collect as much dust as they can. A little speck jolted off the inside of a reed resonator falls through the block and gets caught between the tongue and shallot. No speech.

To the hard-hat wearing, cigar-chewing general contractor, the organbuilder seems like a ninny, fussing about specks of dust. To the member of the vestry that must vote in favor of a huge expenditure to do with flecks of dust, the organbuilder seems like a carpetbagger, trying to sneak an expensive job out of thin air. To the organbuilder, the idea of all that activity, all that disturbance, all that dirt, all those vibrations, and all those workers with hammers, coffee cups, and sandwich wrappings swarming about the organ brings visions of worship made mockery, week after week, by an organ whose lungs are full of everything unholy.

Think about Sunday morning with Widor, Old Hundredth, and all the other festivities, think about valves opening and closing by the millions, and don’t tell me that “a little dust” isn’t going to hurt anything.

§

This lecture is about caring for an organ during building renovation. If your church is planning to sand and refinish the floor, paint the walls and ceiling, replace the carpets (hope not!), or install a new heating and air conditioning system, be sure that the people making the decisions know about protecting the organ from the beginning. Your organ technician can help with advice, and any good organbuilder will be available and equipped to accomplish this important work for you. Any good-quality pipe organ of moderate size has a replacement value of hundreds of thousands of dollars. If yours is a three-manual organ with fifty stops, big enough to have a 32-foot stop, it’s likely worth over a million. The congregation that owns it depends on its reliable operation. A simple oversight can be the end of the organ’s reliability.

When there is no building renovation planned, we can carry these thoughts into everyday life. Institutional hygiene is essential for the reliability of the organ. Remember the custodian sweeping in the basement while you’re practicing? Think of the staff member looking for a place to stow a bunch of folding chairs, finding a handy closet behind the sanctuary. That pile of chairs on the bellows of the organ raises the wind pressure and wrecks the tuning. Or those Christmas decorations leaning up against those strange-looking machines—the roof timbers of the crèche may be leaning against a primary valve. You turn on the organ, draw a stop, and a note is playing continually. Organ technicians usually charge for their travel time. It could be a $300 service call for the right person to realize that a broomstick needs to be moved!

§

When I hear a great organ playing, I often think of those valves in motion. The organist plays a pedal point on the 32′ Bourdon while improvising during Communion, and in my mind’s eye, I can see a five-inch valve held open, with a hurricane of carefully regulated wind blowing into an organ pipe that weighs 800 pounds. A few minutes later, the organist gives the correct pause after the Benediction, swings into a blazing toccata, and thousands of valves open and close each second. Amazing, isn’t it?

Releathering and repairing pneumatic windchests, I’ve made countless valves myself. I know just what they look like and what they feel like. I like to dust them with talcum powder to keep them from sticking years down the road, and I picture what they smell like—the smell of baby powder mingling with the hot-glue pot. Hundreds of times during service calls or renovation jobs, I’ve opened windchests and seen just how little it takes to make a note malfunction. I’ve seen organ blowers located in the filthiest, stinkiest, rodent-filled, dirt-floored, moldy sumps. I’ve seen the everyday detritus of church life—hymnals, vestments, decorations, rummage-sale signs, and boxes of canned goods piled on organ walkboards and bellows, even dumped on windchests loaded with pipes. Can’t understand why the organ sounds so bad. 

Earlier this week, I visited an organ in which the static reservoir and blower were in a common storage space. A penciled sign was taped to the reservoir at chest height: “Please do not place anything on this unit. Sensitive parts of pipe organ. If you have any questions, see Norma.” When we say, “do not place anything,” how can there be questions?

To the untrained eye, the pipe organ may appear as a brute of a machine. But inside, it’s delicate and fragile. If “cleanliness is next to Godliness” in the wide world, cleanliness is the heart of reliability for the pipe organ. Institutional hygiene. Remember that.

John Bishop is executive director of the Organ Clearing House.

Special delivery
The Bath Iron Works (a General Dynamics Company) is about fifteen miles from where we live. Located on the shore of the Kennebec River in Bath, Maine, more than ten miles up from the ocean, they build Aegis and Zumwalt class destroyers for the United States Navy. The shipyard is unique because of its immense lifting capacity—you can see their mammoth cranes from miles in each direction. This allows them to mass-produce ships in large sections because they can lift as much as a third of a ship at once. In the company’s heyday during World War II, they launched a completed destroyer every twenty-two days. Think of the supply chain. That’s a lot of steel—tens of thousands of tons. That’s a lot of wire, windows, pipes, engines, tanks, valves, and gauges. It took about 275,000 person hours to build a ship. Twenty-two days—that’s 12,500 hours a day, or 1250 workers working ten-hour days. To stay efficient, each worker had to have the right tools and the right materials at the right time. Any organbuilder’s head would spin to think of such a management challenge. It’s hard enough to organize 200 person hours per week in a five-person workshop.
In the 1870s and 1880s, E. & G. G. Hook & Hastings was building new organs at the rate of something like one a week. We know that materials were delivered at night to that workshop in Boston by horse-drawn rail cars using the same tracks that the passenger trolleys used by day. Think of the mountains of American black walnut going into the maw of that place, all to be unloaded by hand. I suppose they had a night crew of men who did nothing but unload rail cars and make sure the materials were stored in the right place. And I suppose once the lumber was stored they loaded bales of sawdust to be carted off to line chicken coops.
While we think about the work involved in organizing a flow of materials into a nineteenth-century organ shop, what about the actual work of building the organs? When I started working in organ shops, we had screwdrivers that we turned by hand—analog screwdrivers. For a while we used electric screwdrivers that had wires hanging out of the handles—wires that could flop across the pipes of the Mixture while you were taking down a bottom board of an upper chest to repair a dead note. Now we have rechargeable cordless tools. And to top that, I have a battery charger that runs on the twelve-volt power in my car so I can recharge my power tools between service calls.
I’ve joked with the hypothetical question, “if Bach had a Swell box would he have used it?” I bet Mr. Skinner would have delighted in an eighteen-volt rechargeable DeWalt screw-gun. It’s even got an adjustable clutch to keep you from stripping the threads.

Supply and demand
We live at the end of a half-mile dirt road. I have a swell little workshop at the house where I tackle portions of our projects. I’m especially fond of working on organ consoles and I have a beauty in the shop right now, built by Casavant in 1916. We are renovating the organ for a church in Manhattan and I’m spending the summer plugging away at the console. Our house is at the end of the UPS route. A couple times a week at around 5:30 in the afternoon, the big brown truck hurtles down the driveway and careens into the dooryard. Nuthatches, chickadees, mourning doves, and goldfinches scatter in terror, groundhogs and chipmunks dash into the stone walls—only the sassy and pugnacious little red squirrels seem ready for the challenge.
With diesel engine roaring and spewing, the driver (there are two regulars) turns the truck around so it’s heading home before he’ll even look at me. He tosses a couple boxes at me and blasts off in a cloud of fumes, dust, and pebbles. (If he had to take care of a long dirt road the way I do he’d never drive like that—each time he comes to the house, five shovels of my gravel goes into the woods.) Measuring sound in decibels-per-hour, the UPS guy makes more noise in two-and-a-half minutes than I do in a week.

Leaning to the left
I suppose that if we were at the beginning of the route, the UPS driver would have a little more time to chat, but I remember reading an article that allowed a glimpse into the company’s efficiency. As traffic increases on America’s roads, we are all aware that you can wait a long time for a chance to make a left-hand turn on a busy road. Years ago I fell into the habit of planning errands to avoid left-hand turns. If I go to the hardware store first, grocery store second, bank third, the only left turn is when I leave the grocery store. I got teased about that some, but on December 9, 2007 the New York Times published an article that I believe excused my apparent eccentricity. Titled “Left-Hand-Turn Elimination,” the story told that that UPS has a “package flow” software program that maps out routes for the drivers limiting the number of left-hand turns as much as is practical. UPS operates 95,000 big brown trucks. By limiting left-hand turns they were able to reduce their routes by 28,500,000 miles, save 3,000,000 gallons of fuel, and reduce carbon dioxide emissions by 31,000 thousand metric tons. (Now you know what kind of mileage a UPS truck gets.) You can read the story at <A HREF="http://www.ny times.com/2007/12/09/magazine/09left-handturn.html">www.ny times.com/2007/12/09/magazine/09left-handturn.html</A>. Makes my five shovels of gravel seem a little less important!
After the big brown truck barrels up the driveway and turns right onto the road, I go back into the shop and open the boxes. What goodies I find: silver wire for key-contacts, woven felt for keyboard bushings, snazzy little control panels for solid-state relays and combination actions, specialty wood finishes from a one-of-a-kind supplier, useful tools that you can’t find at Home Depot. It’s like a little birthday party at the end of the day.
I need a huge variety of parts and materials to complete a project like this, and I spend a lot of time on the phone, leafing through catalogues (the big industrial-supply catalogues have more than 3,500 pages) and searching online. I rely on Internet access, next-day delivery, and specialty supply houses. And I can buy just about anything. Let’s say I need some red woven felt (bushing cloth) to replace the bushings in a mechanical part. I can use an X-Acto knife to get the old cloth out of the hole, but it’s really hard to measure the thickness of a piece of felt that was made ninety years ago. So what thickness should I get? Easy. If I search carefully online I can find it in thicknesses graduated by 64ths of an inch. I order a few square feet of four different thicknesses and experiment.

Close enough?
We talk about the importance of duplicating original materials when restoring an instrument. “If Mr. Skinner used 9/64″ red bushing cloth, I’m going to use 9/64″ red bushing cloth.” But I bet Mr. Skinner wasn’t choosing between eight different thicknesses listed on a catalogue page. I think he bought the stuff that was available and made it work.
The expression shutters of this Casavant organ we’re working on turn in bearings of woven felt. There’s a quarter-inch steel pin in each end of each shutter that serves as an axle. The pins turn in holes in wood blocks—those holes are bushed with green woven felt. After seventy years of regular use and twenty years of neglect, that felt is hard and worn. Over the years, organ technicians fixed squeaks and squeals in those shutters by glopping grease, oil, candle wax, mutton tallow, and more recently silicone and WD-40 from spray cans on those bearings.
I could buy Teflon tubing of quarter-inch interior diameter (1/4″ ID) from McMaster-Carr, an industrial supply company in New Jersey. I found it on page 91 of their 3,528-page catalog. It costs $1.28 a foot and comes in five-foot lengths. I could cut it into half-inch lengths (less than five-and-a-half cents each), and drill them into the shade frames to make perfect bearings for the quarter-inch steel axles. I bet it would be a long time before they squeal or squeak. It’s not historic, it’s not good restoration practice, but I bet those shutters would work beautifully for decades. I think I’ll go ahead and make that change. I’m confident that the organists who will play on this organ will never know we did, and I trust that Claver and Samuel Casavant will forgive me. My intentions are good and my conscience is clear.

An expressive conundrum
We have some tree work going on in our yard and one of the crew is a skillful equipment operator. He’s using a light-duty excavator that’s known as a backhoe because the bucket (or shovel) comes back toward the operator as it digs. The machine’s boom has three joints, roughly analogous to the human shoulder, elbow, and wrist, and the bucket compares to the hand, as it can curl under to scoop the earth. Each of the joints is operated by a hydraulic piston—that ingenious machine that uses the pressure of oil to extend or contract. It seems counterintuitive, but the engine of this machine drives no gears at all—its sole purpose is to drive a pump that creates the oil pressure. Even the wheels that drive the tracks are turned by hydraulics. The machine’s controls are valves operated by handles—those valves conduct the pressurized oil to the appropriate pistons.
The operator, a young guy named Todd who’s anticipating the birth of his second child as he digs in our yard, has his feet on the pedals that drive the machine forward and back. He has each hand on a four-function joystick. Each push of a control operates only one function, but Todd moves his hands and wrists in quiet little circles combining the machine’s basic movements into circular, almost human motions. His understanding of his controls is intuitive. He doesn’t have to stop to think, let me see . . . if I pull this handle this way, the bucket will curl under . . . He effortlessly combines the motions to extend the boom and the bucket, sets the teeth in the dirt, and brings the boom toward him as the bucket curls under filling with dirt. He whirls around to empty the bucket on a pile, and as he turns back to the hole, the boom and bucket are extending to be ready for the next scoop, which starts without a pause, a jerk, or a wiggle. He’s operating six or seven functions simultaneously. The power that operates the machine and the nature of the motion are both fluid.
I’ve read that some revered orchestral conductors eschew the pipe organ as an inexpressive instrument because it’s not possible for an organist to alter the volume of a single organ pipe. You press a key, the pipe plays. You pull a handle in a backhoe and the bucket moves in one direction. I can hear my colleague organists gasp as I compare Todd’s backhoe with an elegant musical instrument, but isn’t there a similarity between the two machines? After all, we don’t hesitate to call the pipe organ the most mechanical of musical instruments. And when we press that key, we’re opening a valve to let pressure through to do work. (I have to admit I’m glad we’re not messing around with hydraulic oil near a chancel carpet.)
The organist intuitively manipulates the controls—playing keys, changing stops, pushing pistons, operating expression pedals—and the result is fluid crescendos, accents, beguiling delays, great oceans of sound billowing through the air. Literally, organ music is the result of thousands of switches or levers moving at the will of the organist. That organist has practiced for thousands of hours, mastering the limitations of his or her body, teaching the body to perform countless little motions with ease and grace so the music flows free, denying both the physicality of the player and that of the instrument. Because the machine and player are both well-tempered, the music is infinitely expressive.
And of course we separate the organ from the backhoe. It’s nice to be able to move a ton of dirt in a few minutes without breaking a sweat, and we admire the skill of the guy who can make that machine come alive. But I couldn’t help notice that one of the joints on Todd’s machine has an important squeak to it, enough that when I was back in my workshop or office and couldn’t see the machine, I knew when he was extending or retracting the boom. Not my swell shutters!
A pipe organ is magic when all the squeaks and squeals are gone, when each function of the machine responds effortlessly to the intuitive motions of the player. In the workshop we make thousands of little choices about what material to use, how to adjust it, how to glue it down, so the machine will not stand in the way of the music. In the practice room we hone our skills so no knuckle cracks, no muscle binds, no fingernail hangs, and nothing about our bodies will stand in the way of the music. We dress in clothes that allow us to move freely, and we make sure our shoes are less than two notes wide. Our bodies and our instruments are conduits between the composer’s ideals and the ears of the audience.
Thanks to the UPS guy for bringing all those goodies, and yes—I’m certain that Bach would have used the expression pedal, but only if the shutters didn’t squeak.

John Bishop is executive director of the Organ Clearing House.

Don’t blame the tools
The carpenter is finishing a house. He’s carefully measuring and mitering baseboards, windowsills, and doorjambs. He’s distracted by a mosquito, and his hammer glances the nail creating a carpenter’s rosette. The first thing he does is look at the head of the hammer—must be some glue on it or something.
The same carpenter needs to make one quick cut. He draws a square line on the board and picks up his handsaw. The saw veers to starboard. The first thing he does is look at the saw. Must be dull.
Or he measures a piece with a folding wooden ruler. He makes his mark and cuts his piece, but he didn’t unfold the ruler all the way—the inch markings skip from 13 to 26 and the piece is a foot too short. The first guy to come up with a wood-lengthener or wood-widener is going to make a fortune.
Organbuilders typically have many more tools than most tradesmen because our trade comprises so many facets. Of course, we have lots of woodworking tools, but we also have tools for leather, soft metal, hard metal, electrical work, and some ingenious rigs specific to pipe organs such as pallet spring pliers, tuning cones, toe cones and toehole reamers, and a wide assortment of nasty-looking little spades and prickers for voicing organ pipes.
When I’m working on a job site installing, tuning, or repairing organs, I carry a canvas sailmaker’s tool bag that measures about 8 by 16 inches and 12 inches high when fully loaded. It’s got 24 pockets on its sides and ends that surround a big central cavity. I like this format because you don’t need extra space to open it. Carry a steel toolbox up onto an organ walkboard and you need twice the space for the open lid. I keep it organized so that each tool has a pocket (some pockets have a half-dozen tools in them), and when I’m squeezed in a dark corner in an organ I can put my hands on many of my tools without looking at the bag. When co-workers borrow tools from me, I ask them to leave them on the floor next to the bag so my system doesn’t get messed up.
This morning I unloaded my car after a weeklong trip to one of our job sites, and all my toolboxes are on the long workbench in my shop. I wonder as I write just what’s in the favorite sailmaker’s bag, so I’ll take everything out and count. My everyday tool kit includes:
• 15 screwdrivers (no two alike, including ratchets, stubbies, offsets, straight, Phillips, or Robertson drive—I hope there’s never a screw I can’t reach)
• 2 wire cutters (fine for circuit boards, heavy for larger wires)
• 2 pairs long-nosed pliers (small and large)
• Flat-billed pliers
• Round-nosed pliers (for bending circles and hooks in wire)
• Double-acting linesman pliers (strong enough to let me bend bar steel in my hands, though the last pair broke in half when I did that)
• 1 pair slip-joint pliers
• 2 pairs vise-grips (one small, one long-nosed)
• Sears Robo-grip pliers (inherited from my father-in-law’s kit)
• 6″ adjustable wrench
• 2 sets Allen keys (English and metric)
• 2 pairs of scissors (one specially sharp, one general use)
• 6″ awl
• Tapered reamer
• 3 hemostats (two curved, one straight, for gripping tiny wires)
• Wire stripper (American Wire Gauge 16 through 26)
• 2 flashlights (large and small with spare batteries)
• 2 saws (one reversible back saw, one “harp” hack saw with replacement blades)
• 2 cheap chisels (3/4″ and 1″)
• 35-watt soldering iron and solder (for wiring)
• Electric test light
• 6 alligator clip leads
• Small hammer (my maul-wielding colleagues call it my “Geppetto” hammer)
• 2 rulers (one 35′ tape measure, one 72″ folding rule)
• 2 utility knives (light and heavy)
• 10 files (flat, half-round, round, big-medium-tiny)
• 3 tuning irons
• Pallet spring pliers
• 2.5-millimeter hex-nut driver (for Huess nuts)
• Wind pressure gauge
• 2 rolls black vinyl tape
• Sharpies, ballpoint pens, pencils
• Sharpened putty knife
• Spool of galvanized steel wire (for quick repairs)
• Bottle of Titebond glue
• Tubes of epoxy
• 5 small brushes
And there’s a canvas tool-roller with 35 little pokers, prickers, burnishers, spades, spoons, a bunch of little rods for raising languids, wire twisters, magnets, special keyboard tools, and an A=440 tuning fork.
I often ship this bag on airplanes, wrapping it in a blanket and stuffing it in a duffel bag—checked baggage, of course—and I dread losing it. It would take weeks to reconstruct this tool kit.
In the back of the car I carry three other larger toolboxes, with cordless drills, bit and driver sets, and heavier hammers, multimeter, etc., etc., etc. There’s a big plastic box with 40 dividers for wiring supplies, and another full of “organy” odds-’n’-ends like leather nuts and Huess nuts, felt and paper keyboard punchings, a few spare chest magnets, and some old piano ivories. And finally, a cardboard box full of pieces of leather and felt of almost any description—any large scrap from a workbench project goes into that box.
And I’m always missing something.

Organ transplants
Now that you know what my tool bag looks like, here’s a story that makes me wonder. I got a Saturday call from one of my clients, a large Roman Catholic church with a big organ in the rear gallery. The organ wouldn’t start and there were two Masses that afternoon. I knocked on the door of the rectory to get the key for the organ loft and was greeted by a teenage girl who was volunteering to answer the parish phones on the weekend. She called a priest’s extension and said, “The organ guy is here.”
The priest was a tall, dignified, elderly man, who came down the stairs, invited me into a parlor, and offered me a seat. I carried my tool bag with me and set it on the floor next to my chair. He asked two or three questions before I realized he thought I had something to do with a human organ donation program. I set him straight as politely as I could, asking for the keys to the organ loft while wondering what in the world he thought I was going to do with those tools!

Tool renewal
When I was first running around the countryside tuning organs, the “land line” was our only means of communication. You had to get all your service visits arranged in advance, and if a day’s plan changed because a sexton forgot to turn on the heat, I’d look for a pay phone at a gas station. Now of course we all have phones in our pockets. I usually have mine with me in an organ, not because I intend to interrupt my work taking calls, but because it has a notepad and a voice-memo system that allow me to keep notes while on the job. If I realize I’m missing a tool, I’m out of glue, or I don’t have any fresh batteries along, I make a note, and every couple weeks I spend an hour with my tools, replenishing supplies, sharpening blades, and keeping things in order.

Tool envy
There are many clever people working in tool design—every time I go into a hardware store I notice some neat little innovation: the cordless drill-screwdriver with a little headlight that lights when you pull the trigger; the 4-in-1, then 8-in-1, then 10-in-1 screwdriver (I carry one of those in my briefcase); the little rubber octagonal washer that goes on the end of the flashlight to keep it from rolling. And boy, are they tempting. I buy a ten-dollar hand tool because it’s cool and stuff it in my tool bag. Every now and then there has to be a culling. I guess it’s good news that tools break and wear out. It gives me an excuse to buy new ones.
When I was a hotshot apprentice in Ohio, I bought a fancy set of chisels by mail order. These were the Marples beauties, with maple handles, iron ferrules, and Sheffield steel blades. I paid about a hundred dollars for the set of nine—a huge amount of money for me in 1978. (Those were the years when good new large organs cost $5000 per stop!) I was enough of a beginner that my mentor teased me, saying all I needed now was some wood. But I still have those chisels, and I still have the racks I made to hang them on the wall over my bench. They’re the only workshop chisels I’ve ever owned, and while some of them are a little shorter than they used to be, they sharpen just as easily as when they were new. The iron ferrules mean you can hit the handle pretty hard with a mallet without damaging the tool. They are old friends.
By the way, also hanging on the wall over my bench in that shop was a display of my mistakes, hung there by my mentor to keep me humble. I think they’re still there.
When I started the Bishop Organ Company in 1987, I bought a Rockwell-Delta 10″ table saw—it’s known as a “Uni-Saw” and it must be one of the most popular table saw models ever made. The blade can be tilted to make angled cuts, and there’s a crosscut miter gauge that allows me to cut angled ends of boards. Over more than 20 years, I’ve cut miles of wood with it, and only last month I had the first trouble with it. The arbor bearings had finally worn out, and I found a local industrial supply company that was able to replace the bearings quickly. It was such a pleasure to use my saw again with the new bearings that I treated it to a new Freud carbide-tipped blade.

A reflection of attitude
The organbuilding firm of E. & G.G. Hook was most active in Boston in the second half of the nineteenth century. There’s a legend handed down through generations of workers there that in order to be hired to work in the factory an applicant had to present his toolbox for inspection. In the days before Sears, Home Depot, Woodworker’s Warehouse, Woodcraft Supply, Duluth Trading Company, McMaster-Carr, and Grainger, a woodworker built himself a box to store and transport his tools. Remaining examples show infinite attention to detail, with special drawers and cubbies designed for each specific tool, fancy dovetail joints, and hidden compartments. The worker that could produce such a masterpiece could build anything required in an organ shop.
Recently I noticed that Lowe’s was featuring a new line of mechanics’ toolboxes. These were not the little boxes you’d carry around, but monumental affairs with dozens of steel drawers on ball-bearing slides and heavy-duty casters. Some were five and six feet wide and just as tall. Fully loaded they’d weigh a ton or more. I’ve seen things like these for years in mechanics’ service bays and I have a more modest version in my shop, but I’d never seen a toolbox with a built-in refrigerator! Not a bad idea, though.
You may have seen the traveling salesmen who peddle tools to mechanics. The companies are Snap-On, Cornwell, and Matco, among others. A heavy mobile tool showroom pulls up to a service station and the mechanics all come out to shop. The driver is a franchise owner who travels a regular route of customers. He extends credit to his customers, allowing them to make cash payments each week so the wives never learn how much money the guys are spending on tools. And the Snap-On driver is likely to be armed. He’s carrying hundreds of thousands of dollars worth of tools that every mechanic would love to own.

A tool for every purpose
I take a lot of pleasure in my tools. I know, I know—it’s a guy thing, as my wife often mentions (though her weaving habit depends on an in-house service department!). But maintaining a comprehensive and effective tool kit is essential to good organbuilding. We say don’t blame the tools, but we cannot work without them. It’s a simple pleasure to draw a sharp knife along a straight edge to cut a neat piece of leather. I enjoy the sound and sight of plane shavings curling off my workpiece onto my hands and wrists, littering the workbench and floor with aromatic twists. It brings to mind the cute little Christmas dolls made from plane shavings in places like Switzerland—Saint Nicolas with a curly beard of cedar shavings. Moving the languid of an organ pipe to achieve good musical speech, soldering wires to a row of pins that wind up looking like a row of jewels, gluing goat-skin gussets to the corners of a reservoir are all motions repeated countless times that I don’t take for granted and can’t repeat without my tools. When I use someone else’s tools they feel funny in my hands.
Sometimes I’m asked how we can maintain patience to complete a project that might take a year or more. Easy—every day you take satisfaction in each little thing you make. A finished organ comprises thousands of those little projects blended into a unified whole. Listening to an instrument brings back the memories of each satisfying cut, each problem solved, and of course each mistake. My tools are my companions and my helpers. They’ve been with me to almost every American state and as far abroad as Madagascar. Right now they’re all spread out on my workbench for a photo shoot, but they’ll be back at work on Monday morning. 

John Bishop is executive director of the Organ Clearing House

Appreciating depreciation
When a business owner purchases a machine, it becomes an asset of the company, and its value is spread out over a period of years of tax returns. In some cases, the value of a machine is spread out across the cost of doing business. For example, most pipe organ builders own a table saw. A table saw is a piece of stationary equipment with a circular saw blade that’s ten, twelve, fourteen, or maybe sixteen inches in diameter, depending on the size of the machine. There are saws with bigger diameter blades, but they are not so common, and they can be pretty scary.
The blade is mounted on an arbor (shaft) turned by an electric motor. The name of the machine is derived from the milled iron table through which the saw blade emerges. The accuracy of the machine depends on the exact relationship of the blade to the table. Most of the time the blade is set at 90º to the table, so the cut edge of a board is perfectly square to the face that was against the table. The angle of the blade is adjustable in most table saws, so when you want the edge of the board to be 30º off square, you turn a crank that swivels the internal works—motor, arbor, and blade all move together.
There’s a sliding fence that is square to the table and parallel to the blade. The woodworker sets the distance between the blade and the fence to set the width of the board he’s cutting.
The table saw is running a lot in a busy organ shop. Nearly every piece of wood in the organ—from the tallest supports of pedal towers to the tiniest trackers—goes across that machine.
The cost of the machine is depreciated on the company’s tax returns, but the use of the table saw is not usually billed directly against the cost of the organ. It’s part of the cost of doing business. The other basic machines are the cut-off saw (which cuts boards to length), jointer (with a drum-shaped blade that planes one surface smooth and then another smooth face that’s square to the first one), and thickness planer (that works off the jointed face of a board to bring the opposite face parallel and flat). A piece of wood is typically jointed first so an edge and a face are both flat and square to each other, run through the thickness planer so the two faces are parallel and the board is the correct thickness, and passed through the table saw so the two edges are parallel and square to the faces and the board is the correct width. With all that done, the true and square board is cut to length. It takes four machines to cut one board.
A workshop adage is measure twice, cut once. The first person to invent a machine that will lengthen a board is going to be rich and famous, just like the inventor of the magnet that will pick up a brass screw.

$400 an hour for man and machine
You need to put a bell in a church tower, so you hire a rigging company. They show up with the bell strapped on the back of flatbed truck and a big mobile crane. Sometimes you see these cranes on the highway heading to a job. They’re huge and have ten or twelve wheels. They’re very heavy to provide a stable platform for heavy lifting. The steering gears are fascinating—maybe the front three axles are involved in steering. You might think that turning the steering wheel would move all the wheels the same, but if that were the case the machine would hop around corners and eventually break itself apart because the paths of the different axles actually need to be concentric circles. In fact, each axle turns a different amount to allow those concentric circles. Once you know that you can see it easily. It takes some pretty fancy figuring at the drawing board to get it right.
I don’t know actual figures, but I’ll take a stab at the cost of such a machine. Let’s say the machine cost $600,000. The tires are worth $3,000 each. The company bills the customer $400 an hour. Maybe $100 of that is the cost of the operator and the operation—fuel, insurance, excise taxes, maintenance. So $300 an hour is applied to the cost of the machine. At that rate, the machine is paid for in 2,000 hours. There are 2,000 hours in a working year. But the owner of the machine probably can’t keep the machine busy with billable hours all the time. Maybe it takes three or four years to make 2,000 billable hours. After that, every hour billed for the use of the machine is clear money for the owner.
When I was in high school, my home church commissioned a new organ from one of the premiere builders of mechanical-action instruments. It had twelve stops with preparation for six more. The preparation meant that toeboards and rackboards were in place with center holes marked, there was space on all the stop-action rails for additional actions, and there were plugged holes on the console for additional knobs. The original cost of the organ was $36,000. The additional stops were added about ten years later—they cost nearly as much as the original organ. Today, the same organ with eighteen stops would cost $500,000 or more. And this is a relatively small organ.
After looking at those figures, it’s easy to see that a three-manual organ with 50 stops is going to cost more than a million dollars. A million dollars for a pipe organ—the organbuilder must be making a killing. But when the contract is signed, the organbuilder buys ten tons of exotic hardwoods and fancy metals, and commits 10,000 person-hours to the project. He’s paying income tax, payroll taxes, liability insurance, worker’s compensation insurance. He’s spending a lot of time researching, planning, designing, and drawing. And he’s operating a workshop with all those machines and enough (heated) space to handle the instrument. It’s not easy to make ends meet.
So the organ is installed. It cost a million dollars. I wonder if we can pay for it with a concert series. Let’s say there are 500 seats in the church, and let’s charge $20 a seat. That’s box office revenue of $10,000 for each concert. It only takes 100 concerts to pay for the organ. But wait. How often have you seen a 500-seat church filled to capacity for an organ recital? And who’s going to pay $20?
Say $10 then, and 100 people at each recital. Now it takes 1,000 recitals to pay for the organ. And we haven’t heated the building, tuned the organ, paid for electricity to run the blower and light the church, paid the recitalists, or even bought the cider and doughnuts for intermission. And if we’re doing ten concerts a year we’re talking about 100 years. We’ll have to releather the organ at least once—and 60 years from now that will probably cost close to the organ’s original price.
It’s a terrible business plan. You’ll never get your money back out of it. You’re better off buying a crane.

What’s missing?
Meeting with the vestry or board of trustees of a church to discuss an organ project, I have often heard a question that sounds like this: “We’ve got a furnace to replace, a parking lot to pave, a roof to repair, and the city says we have to put in an elevator and bunch of ramps. What’s this unit going to cost?”
I don’t like to think of a pipe organ as a unit. And I don’t think the organ belongs on the list with the potholes in the parking lot or shingles on the roof. It goes on the list with communion silver and stained glass windows. It’s an expression of our faith. It enhances our worship. It raises our spirits. It facilitates our communal singing. Where else in our society do we sing together so regularly and with such purpose?
Our music has evolved from natural laws. On a sunny afternoon in 540 BC on the island of Samos in the Ionian Sea, 30-year-old Pythagoras was walking past a blacksmith shop. There were several smithies at work inside, and our friend Thagos noticed that the hammer blows were producing different pitches. He went inside and watched for a while. At first he thought that a heavier hammer made a lower pitch and a lighter hammer made a higher pitch, but after a little while he noticed that the pitch was determined by the anvil, not the hammer. An anvil would produce the same pitch whether struck with a heavy or a light hammer.
The bell in the temple works the same way—it produces the same pitch when hit with a sledge hammer or a soda can.
With this information in mind, Thagos noticed that there were secondary pitches audible in the tone of an anvil or bell. He set up a cord under adjustable tension that would produce a variety of tones and duplicated the various sounds he was hearing in a single tone. He realized that each different “overtone” represented a ratio to the original pitch: 2:1 (octave) was the first one, 3:2 (fifth) was the second, 4:3 was the third (fourth), etc. And he realized that a series of 13 consecutive fifths would take him back to the original pitch displaced by octaves. These formulas are easy enough to understand, but the original discovery was amazing.
Here’s another example of an extraordinary mathematical observation. A perfect cone is one in which the height of the cone and diameter of its base are equal. The cool fact is that a perfect cone is half the volume of the sphere with the same diameter.
All through his life, Pythagoras worked on these theories, developing systems of altering, or tempering, the intervals to increase the consonance. In simple words, he messed with the math to make it sound better.
The concept of the interval came from the physical world. Next, musicians thought it would sound great to sing in two or more parallel parts using a given interval, and using the scale of notes that had been derived from the natural overtones. It’s easy to imagine the moment when a couple singers, either by design or by error, sang in opposite directions rather than parallel motion. (I think it was by mistake!) They started with a fifth. One went up a note while the other went down a note and they were singing a third. It reminds me of a television ad campaign featuring a collision between a truck carrying peanut butter and one carrying chocolate.
Did it take 1,000 years to get from Thagos’s blacksmith shop to a couple monks messing up while singing in parallel motion? If so it took another 1,500 years to evolve the rules of four-part harmony through Bach’s 371 Chorales, Mozart’s symphonies, Mendelssohn’s oratorios, and Saint-Saëns’ piano concertos. Enter Debussy, Stravinsky, and Alban Berg.
With all that development of the theory of music came the development of the panoply of musical instruments. The physics of each instrument represents another exploitation of the overtone series. Change a pitch by doubling or halving the number of cycles-per-second and you jump an octave. Change by a factor of 3:2 and you jump a fifth. Hit a string and you get one tone. Stroke a string and you get another. Blow into a tube, blow through a reed, etc., etc. It all started with the hammer and anvil.
By the way, thinking about the evolution of music, I think that Debussy discovered the whole-tone scale in church. The interiors of most pipe organs are arranged in whole tones. The proof of that is the symmetry of most organ cases. Low C is on one side of the case, C# on the other, D is next to C, D# is next to C#, and so on. Among other things, this distributes the weight of the organ evenly from side to side. The organ tuner goes up one side first, then the other side—otherwise he’d be jumping back and forth across the organ for each new note.
It sounds like this: C-next, D-next, E-next, F#-next, G#-next, A#-next, etc. Claude D. walked along the river bank, got a good impression noticing Claude M. painting pictures of the same cathedral day after day, went into the cathedral to hear the organ playing scales in whole tones—another good impression. Bet it was Aristide Cavaillé-Coll tuning the organ. Did you know he was the inventor of the circular saw blade?
In the fourteenth century AD, the organ was among the most complicated devices built by mankind. In the early twentieth century, organbuilders were creating the first user-programmable binary computers. They were bulky, made of wood, leather, and metal, ran on electro-pneumatic power, and had memories of about .001KB. But the user could program them. Amazing. Push a button with your thumb and you have the registration for verse three. The organ is the most mechanical of all musical instruments—an oxymoron, a conundrum.
Organbuilder Charles Fisk talked about the magic of all that air being turned into musical sound. Think of the air as fuel. Burn some air and you get a toccata. Or burn some air and you play a hymn. Share the air around the room, and the organ and the congregation can do the same hymn.
All of that Samian observation, all of that math, all of that experimentation brought us to that million-dollar organ. It all comes from natural laws interpreted by a healthy dose of human reason, wonder, trial, and error. The organ may be the most mechanical of all musical instruments, but it’s not a machine. It’s not a unit. It’s a gift. It’s the gift that keeps on giving until it needs to be releathered. You can’t pay for it by selling its use by the hour. You can’t justify it as a business expense. It’s not practical, it’s not even necessary. But it feeds the soul. It’s just that simple. 

John Bishop is executive director of the Organ Clearing House.

Measure up
When I was an apprentice working in Oberlin, Ohio, we had a particularly bad winter, with several heavy storms and countless days of difficult driving conditions. As part of our regular work, my mentor Jan Leek and I did a great deal of driving as we serviced organs throughout northeastern Ohio and western Pennsylvania. Jan owned a full-size Dodge van—perfect for our work as it was big enough to carry windchests, big crates of organ pipes, and long enough inside to carry a twelve-foot stepladder with the doors closed, if the top step was rested on the dashboard near the windshield. All those merits aside, it was relatively light for its size and the length of its wheelbase, and it was a simple terror to drive in the snow. There can’t have been another car so anxious to spin around.
Jan started talking about buying a four-wheel-drive vehicle, and one afternoon as we returned from a tuning, he turned into a car dealership and ordered a new Jeep Wagoneer—a large station wagon-shaped model. He wanted it to have a sunroof, but since Jeep didn’t offer one he took the car to a body shop that would install one as an aftermarket option. As we left the shop, Jan said to the guy, “I work with measurements all day—be sure it’s installed square.” It was.
Funny that an exchange like that would stick with me for more than thirty years, but it’s true—organbuilders work and live with measurements all day, every day they’re at work. A lifetime of counting millimeters or sixty-fourths-of-an-inch helps one develop an eye for measurements. You can tell the difference between 19 and 20 millimeters at a glance. A quick look at the head of a bolt tells you that it’s seven-sixteenths and not a half-inch, and you grab the correct wrench without thinking about it. Your fingers tell you that the thickness of a board is three-quarters and not thirteen-sixteenths before your eyes do. And if the sunroof is a quarter-inch out of square, it’ll bug you every time you get in the car.
And with the eye for measuring comes the need for accuracy as you measure. Say you’re making a panel for an organ case. It will have four frame members—top, bottom, and two sides—and a hardwood panel set into dados (grooves) cut into the inside edges. The drawing says that the outside dimensions are 1000mm (one meter) by 500mm (nice even numbers that never happen in real life!). The width of the frame members is 75mm. You need to cut the sides to 1000mm, as that’s the overall length of the panel. But the top and bottom pieces will fit between the two sides, so you subtract the combined width of the two sides from the length of the top and bottom and cut them accordingly: 500mm minus 75mm minus 75mm equals 350mm.
You make a mark on the board at 350mm—but your pencil is dull and your mark is 2mm wide. Not paying attention to the condition of the pencil or the actual placement of the mark, you cut the board on the “near” side of the mark and your piece winds up 4mm too short. The finished panel will be 496mm wide. Oh well, the gap will allow for expansion of the wood in the humid summer. But wait! It’s summer now. In the winter your panel will shrink to 492mm, and the organist will have to stuff a folded bulletin into the gap to keep the panel from rattling each time he plays low AAA# of the Pedal Bourdon (unless it’s raining).
You can see that when you mark a measurement on a piece of wood, you must make a neat clean mark, put it just at the right point according to your ruler, and remember throughout the process on which side of the mark you want to make your cut. If you know your mark is true and the length will be accurate if the saw splits your pencil mark, then split the pencil mark when you cut!
I’ve had the privilege of restoring several organs built by E. & G.G. Hook, and never stop delighting at the precision of the 150-year-old pencil marks on the wood. The boys in that shop on Tremont Street in Boston knew how to sharpen pencils.
Another little tip—use the same ruler throughout the project. As I write, there’s a clean steel ruler on my desk that shows inches with fractions on one edge and millimeters grouped by tens (centimeters) on the other. It’s an English ruler exactly eighteen inches long, and the millimeter side is fudged to make them fit. The last millimeter is 457, and the first millimeter is obviously too big. If I were working in millimeters and alternating between this ruler and another, I’d be getting two versions of my measurements. While the quarter-millimeter might not matter a lot of the time, it will matter a lot sometimes. I have several favorite rulers at my workbench. One is 150mm long (it’s usually in my shirt pocket next to the sharp pencil), another is 500, and another is 1000. I use them for everything and interchange them with impunity because I know I can trust them. With all the advances in the technology of tools I’ve witnessed and enjoyed during my career, I’ve never seen a saw that will cut a piece of wood a little longer. The guy who comes up with that will quickly be wealthy (along with the guy who invents a magnet that will pick up a brass screw!).
My wife Wendy is a literary agent, with a long list of clients who have fascinating specialties. In dinner-table conversations we’ve gone through prize-winning poets, crime on Mt. Everest, multiple personalities, the migration of puffins, flea markets, and teenagers’ brains (!). Her client Walter Lewin is a retired professor from the Massachusetts Institute of Technology, who is famous for his rollicking lectures in the course Physics 8.01, the most famous introductory physics course in the world. On the first page of the introduction to his newly published book, For the Love of Physics: From the End of the Rainbow to the Edge of Time—A Journey Through the Wonders of Physics, Lewin addresses his class: “Now, all important in making measurements, which is always ignored in every college physics book”—he throws his arms wide, fingers spread—“is the uncertainty of measurements . . . Any measurement that you make without knowledge of the uncertainty is meaningless.” I’m impressed that Professor Lewin thinks that inaccuracy is such an important part of the study of physics that it’s just about the first thing mentioned in his book.
The thickness of my pencil lines, my choice of the ruler, and the knowledge about where in the line the saw blade should go are uncertainties of my measuring. If I know the uncertainties, I can limit my margin of error. I do this every time I make a mark on a piece of wood. And by the way, if you’re interested at all in questions like “why is the sky blue,” you’ll love Lewin’s book. And for an added bonus you can find these lectures on YouTube—type his name into the search box and you’ll find a whole library. Lewin is a real showman—part scientist, part eccentric, all great communicator—and his lectures are at once brilliantly informative and riotously humorous.
Now about that panel that will fit into the dados cut in the frame members. Given the outside dimensions and the width of the four frame pieces, the size of the panel will be 850mm x 350mm (if your cutting has been accurate). But don’t forget that you have to make it oversize so it fits into the dado. 7.5mm on each side will do it—that allows for seasonal shrinkage without having the panel fall out of the frame. So to be safe, cut the dados 10mm deep allowing a little space for expansion, and cut the panel to 865mm x 365mm—that’s the space defined by the four-sided frame plus 7.5mm on each side, which is 15mm on each axis. Nothing to it.
Now that you’ve all had this little organbuilding lesson, look at the case of a good-sized organ. There might be 40 or 50 panels. That’s a lot of opportunity for error and enough room for buzzing panels to cover every note of the scale.

§

For the last several days I’ve been measuring and recording the scales and dimensions of the pipes of a very large Aeolian-Skinner organ that the Organ Clearing House is preparing to renovate for installation in a new home. I’m standing at a workbench with my most accurate measuring tools while my colleague Joshua Wood roots through the pipe trays to give me C’s and G’s. Josh lays the pipes out for me, I measure the inside and outside diameters, thickness of the metal (which is a derivative of the inside and outside diameters—if outside diameter is 40mm and the metal is 1mm thick, the inside diameter is 38mm. I take both measurements to account for uncertainties.), mouth width, mouth height, toehole diameter, etc. As I finish each pipe, Josh packs them back into the trays. With a rank done, we move the tray and find another one. Now you know why I’m thinking about measurements so much today.
When studying, designing, or making organ pipes, we refer to the mouth-width as a ratio to the circumference, the cut-up as a ratio of the mouth’s height to width, and the scale as a ratio of the pipe’s diameter to its length. If I supply diameter and actual width of the mouth, the voicer can use the Archimedian Constant (commonly known as π - Pi) to determine the mouth-width ratio, and so on, and so forth.
Here’s where I must admit that my knowledge of organ voicing is limited to whatever comes from working generally as an organbuilder, without having any training or experience with voicing. My colleagues who know this art intimately will run circles around my theories, and I welcome their comments. From my inexpert position, I’ll try to give you some insight into why these dimensions are important.
The width of the mouth of an organ pipe means little or nothing if it’s not related to another dimension. Using the width as a ratio to the circumference of a pipe gives us a point of reference. For example, a mouth that’s 40mm wide might be a wide mouth for a two-foot pipe, but it’s a narrow mouth for a four-foot pipe. A two-foot Principal pipe with diameter of 45mm might have a mouth that’s 40mm wide—that’s a mouth-width roughly 2/7 of the circumference, on the wide side for Principal tone. The formula is: diameter (45) times π (3.1416) divided by mouth-width (40). In this case, we get the circumference of 141.372mm. Round it off to 141, divide by 40 (mouth-width), and you get 3.525, which is about 2/7 of 141. Each time I adapt the number to keep things simple, I’m accepting the inaccuracy of my measurements.
The mouths of Flute pipes are usually narrower (in ratio) than those of Principals. Yesterday I measured the pipes of a four-foot Flute, which had a pipe with the same 40mm mouth-width, but the diameter of that pipe was about 55mm. That’s a ratio of a little less than 1/4. The difference between a 2/7 mouth and a 1/4 (2/8) mouth tells the voicer a lot about how the pipe will sound.
And remember, those diameters are a function of the scale, the ratio of the diameter to the length. My two example pipes with the same mouth width are very different in pitch. The Principal pipe (45mm in diameter) speaks middle C of an eight-foot stop, while the Flute with the 40mm mouth speaks A# above middle C of an eight-foot.

§

You can imagine that the accuracy of all these measurements is very important to the tone of an organ. The tonal director creates a chart of dimensions for the pipes of an organ, including all these various dimensions for every pipe, plus the theoretical length of each pipe, the desired height of the pipe’s foot, etc. The pipemaker receives the chart and starts cutting metal. Let’s go back to our two-foot Principal pipe. Diameter is 45mm. Speaking length is two feet, which is about 610mm. Let’s say the height of the foot is 200mm. The pipemaker needs three pieces of metal—a rectangle that rolls up to become the resonator, a pie-shaped piece that rolls up into a cone to make the foot, and a circle for the languid.
For the resonator, multiply the diameter by π: 45 x 3.1416 = 141.37mm (this time I’m rounding it to the hundredth)—that’s the circumference of the pipe, so it’s the width of the pipemaker’s rectangle. Cut the rectangle circumference-wide by speaking-length-long: 141.37 x 610.
For the foot, use the same circumference and the height of the foot for the dimensions of the piece of pie: 141.37mm x 200.
Roll up the rectangle to make a tube that’s 45mm in diameter by 610 long, and solder the seam.
Roll up the piece of pie to make a cone that’s 45mm in diameter at the top and 200mm long, and solder the seam.
Cut a circle that’s 45mm in diameter and solder it to the top of the cone, then solder the tube to the whole thing. (I will not discuss how to cut the mouth or form the toehole.)
But Professor Lewin’s adage reminds us that no pipemaker is ever going to be able to cut those pieces of metal exactly 141.37mm wide. That’s the number I got from my calculator after rounding tens-of-thousandths of a millimeter down to hundredths. You have to understand the uncertainty of your measurements to get any work done.

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As I take the measurements of these thousands of organ pipes, I record them on charts we call scale sheets—one sheet for each rank. I reflect on how important it is to the success of the organ that this information be accurate. I’m using a digital caliper—a neat tool with a sliding scale that measures either inside or outside dimensions. The LED readout gives me the dimensions in whatever form I want—I can choose scales that give inches-to-the-thousandth, inches-to-the-sixty-fourth, or millimeters-to-the-hundredth. I’m using the millimeter scale, rounding hundredths of a millimeter up to the nearest tenth. As good as my colleagues are and as accurately as they might work, they’re not going to discern the difference between a mouth that’s 45.63mm wide from one that’s 45.6mm.
And as accurately as I try to take and record these measurements, what I’m measuring is hand made. I might notice that the mouth of a Principal pipe is 16.6mm high on one end and 16.8mm high on the other. A difference of .2mm can’t change the sound of the pipe that much—so I’ll record it as 16.7. I know the uncertainties of my measurements. I adapt each measurement at least twice (rounding to the nearest tenth and adapting for uneven mouth-height) in order to ensure its accuracy. Yikes!

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Earlier I mentioned how people who work with measurements all the time develop a knack for judging them. I’ve been tuning organs for more than 35 years, counting my way up tens of thousands of ranks of pipes, listening to and correcting the pitches, all the time registering the length of the pipes subconsciously. With all that history recorded, if I’m in an organ and my co-worker plays a note, I can reach for the correct pipe by associating the pitch with the length of the pipe.
π (pi) is a magical number—that Archimedes ever stumbled on that number as the key to calculating the dimensions of a circle is one of the great achievements of the human race. How can it be possibly be true that πd is the circumference of a circle while πr2 is the area? Here’s another neat equation. A perfect cone is one whose diameter is equal to its height. The volume of a perfect cone is exactly half that of a sphere with the same diameter. How did we ever figure that one?
There are no craftsmen in any trade who understand π better than the organ-pipemaker. When you visit a pipe shop, you might see a stack of graduated metal rectangles destined to be the resonators of a rank of pipes. The pipemaker knows π as instinctively as I can tell that the first millimeter on my ruler is too big. Imagine looking at a tennis ball and guessing its circumference!

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When you’re buying measuring tools, you must pay attention to accuracy. Choose an accurate ruler by comparing three or four of them against each other and deciding which one is most accurate. Choose an accurate level by comparing three or four of them. You’ll be surprised how often two levels disagree. Just as mathematics gives us the surety of π, so physics gives us the surety of level. There is only one true level!
I’ve been showing off all morning about how great I am with measurements in theory and practice, so I’ll bust it all up with another story about van windshields. I left the shop to drive to the lumberyard to pick up a few long boards of clear yellow pine. They had beautiful rough-cut boards around thirteen feet long, eight and ten inches wide, and two inches thick. Each board was pretty heavy, and as they were only roughly planed, it was easy to get splinters from them. I put the first one in the car, resting the front end on the dashboard right against the windshield. Perfect—the door closed fine, let’s get another. I slid the second one up on the first, right through the windshield. Good eye! 

John Bishop is executive director of the Organ Clearing House.

Expressly expressive
I once heard an orchestral conductor state that the pipe organ is not an expressive instrument because the player cannot alter the volume of a single pipe. This ignorant statement was part of his argument against including an expensive new organ in an even more expensive new concert hall.
One might respond that most of the instruments of the symphony orchestra are unmusical because they can only play one note at a time. By saying “most” I’m excepting the strings of course, which can play two notes at time—maybe three under special circumstances. So an orchestra (by definition) needs many instruments to play music, expressively or not.
Aha! In order for the organ to be an expressive instrument, it comprises thousands of pipes. And big groups of those pipes are enclosed in wonderful expression machines that give the organist all sorts of control over dynamics.
The first Swell boxes were pretty simple affairs made of light wood with a few shutters in front that were operated by a lever near the floor. You could push the lever down and a little sideways with your foot to latch it open, you could let it slam closed, or you hold it halfway open, calf muscles a-trembling. Rigs like this are found on very old English organs, and there are quite a few nineteenth-century American organs that still have expression boxes like that. In 1996 I restored an organ built by E. & G.G. Hook in 1868 that had a “ratchet” Swell pedal. There was a sort of stationary wooden gear whose teeth could arrest the motion of the pedal in five or six different places. You could push the pedal a certain way to release the ratchet or you could leave the shutters partially open at any of those positions. And it was a good idea to release the ratchet as you opened the shutters—otherwise they said “click-click-click” as they opened.
The development of the mechanical balanced Swell pedal was a pretty big deal. Most American organs built between 1870 and 1900 have them. A sturdy mechanical linkage connects the pedal to the shutters. Because gravity works on horizontal shutters, balanced Swell shutters are almost always vertical. You can take your foot off the Swell pedal and the shutters stay still right where you left them. The only problem is that you have to remember to leave the shutters open when you’re finished playing to allow the temperature inside the Swell box to stay as close as possible to the ambient climate of the organ. Leaving the shutters closed typically results in a different temperature inside the Swell box so the Swell won’t be in tune with the Great. That’s not too big a deal because as soon as you open the shutters the temperature will moderate and the pitches will come back together—so if you’re halfway home and realize you’ve forgotten to leave the Swell pedal open, don’t worry about it too much!
If you get halfway home and wonder if you’ve left the blower running, then you’d better go back to the church.
And by the way, in most electro-pneumatic organs, the shutters are held open by springs, so when the organ is turned off the shutters open, no matter what position the pedal was left in.

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During the Great Revival of classic styles of organbuilding in the second half of the twentieth century, many of us got used to playing organs that had no expression enclosures. Twenty years into that movement, shutters started finding their way back into organs, and today new organs are built with very sophisticated collections of expression chambers including double expressions—those fancy divisions in which an expression box that encloses ten stops might also enclose another expression box with five or six stops. It’s mighty effective when either very powerful voices (Tuba) or very soft voices (Unda Maris) are double-enclosed. The Tuba can start from nothing and Swell to a roar, and the Unda Maris can start from a whisper and vanish into thin air.
I often write about the organ as the most mechanical of instruments. (I’m glad that opinionated ignorant conductor didn’t wade into this pond!) A large organ, especially with electro-pneumatic action, can look like a mysterious mechanical monster inside. It’s no wonder that the sexton of your church mistakes it for a furnace room and piles it full of folding chairs. (You shouldn’t be storing chairs in the furnace room either.)
The organbuilder is forever challenged by the conflict between the organ’s mechanical identity and its artistic purpose. If the music is interrupted by too much mechanical noise, the effect is diminished.
The expression shutters can be the biggest culprit. Who among us has not sat through a recital or a worship service marred by a squeaking Swell shutter? I once attended a choral concert in a conservatory concert hall in which several pieces were accompanied on the organ. The Swell shutters were exposed as part of the façade, they squeaked, and the organist had an annoying habit of beating time with the Swell pedal. Flap-flap-flap, squeak-squeak-squeak was all we could hear.
I’ve made lots of service calls to correct squeaking shutters. Often enough a little squirt of oil or silicone is all that’s needed—that’ll be $200 for the travel and time and four cents for the squirt.

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For the organist, the ideal expression shutters can silence the division when closed and allow it to roar when open. They can open or close in a nano-second, and if you operate the pedal slowly they provide infinite gradation of volume —no jerking from one stage to the next. OK, we’ll see what we can do.
In order to achieve really effective expression, the box and its shutters must be massive. If you build a Swell box and shutters out of three-quarter-inch-thick wood, you’re building more of a soundboard than an enclosure.
Let’s start with the fabric of the box. The walls and ceiling of the box should both deaden and reflect the sound of the organ. Deaden—so when the shutters are closed there’s no resonance going on. Reflect— so no sound is lost or absorbed by the interior surfaces. In other words, the sound should be effectively contained when the shutters are closed and when the shutters are open the sound should be propelled out through them.
Organbuilders have experimented with all sorts of construction styles. The simplest is heavy soft wood. Use two-inch-thick pine for the walls and you’re doing pretty well. Try two one-inch-panels with an airspace between. Just as massive, but the airspace cuts down the transmission of vibration. How about fill the airspace with sawdust? That works great—the sawdust really absorbs sound so the box is most effective when closed. But it’s a real drag when you’re surprised by fifteen cubic feet of sawdust pouring out by accident when you’re dismantling an organ.
There’s a material called MDF (maximum density fiberboard). It is manufactured in 4′ x 8′ sheets like plywood. It’s made from a sophisticated recipe, but it can be described simply as sawdust and glue cast into sheets. A sheet of three-quarter-inch plywood weighs about 65 pounds, heavy enough. But the same size sheet of MDF weighs 96 pounds. We have built a number of expression boxes using double-thicknesses of MDF. It’s hard work because the stuff is so heavy, and because it’s so dense it’s hard to cut—it burns up saw blades like kindling wood. But it sure makes an effective tonal enclosure.
My first work in organbuilding shops focused mostly on classic-style mechanical-action organs. It was from that bias I heard or read that E. M. Skinner had built cement swell boxes. Cement swell boxes? How decadent. What I pictured was the newly poured foundation of a house with rebar (steel reinforcement bars) sticking up out of it. How could that be musical? But when I finally worked on an organ that had such a thing I realized that my youthful and ignorant bias was exactly that—a youthful and ignorant bias. In fact, the “cement” swell box has a structure of studs and joists something like normal wood-frame construction with heavy plaster surfaces, and a finish coat of Keene’s Cement, which is an anhydrous calcined gypsum mixed with an accelerator used as a hard finish, or more to the point, hard plaster. The heavy structure of the walls and ceiling deaden the sound and the Keene’s Cement surface reflects it—the best of both worlds. The expression chambers of the mighty Skinner/Aeolian-Skinner organ at the Cathedral of St. John the Divine in New York are built as free-standing rooms in the huge spaces some 90 feet up above both sides of the chancel. The walls are thick and heavy, and the surfaces are finished with Keene’s Cement, and those powerful reeds sure go quiet when the shutters are closed.

I shudder to think
What about the shutters? Just like the boxes, there are lots of ways to build expression shutters. They are usually made of wood, ideally an inch-and-a-half thick or more. The edges are usually beveled so they effectively overlap when closed. The edges of the shutters where they come in contact with one another usually have heavy felt or some other soft material glued to them so they close quietly and tightly. Some builders make shutters out of metal and we’ve even seen them made of glass and Plexiglas. Just like the walls of the expression chamber, the best shutters are massive and shaped and fit so they close really tight. The more massive, the more they contain the sound of the organ.
The shutters are mounted in frames—we call them expression frames. Sometimes the shutters are vertical, sometimes horizontal. As I said earlier, it’s easiest to build a balanced mechanical expression action if the shutters are vertical—that way there’s no effect of gravity on the weight of the shutters. All you have to balance is the action itself.
Shutters are mounted in the expression frames with some kind of rotary bearing to allow the shutters to pivot. Most often you find a strong steel pin (axle) that pivots in a hole drilled in hard wood. The holes and pins are greased, and if the shutters are vertical, the bottom bearing is figured out so as to keep the shutter high enough that it doesn’t rub against the wooden frame. In fact, those bottom bearings are often adjustable—if the shutter settles and starts squeaking against the frame, you can raise it with a turn of a screw.
Some organbuilders go the extra mile and use commercial ball bearings for mounting expression shutters.
It’s also ideal for the shutters to be easily removable. In many organs it’s necessary to remove shutters in order to tune, but you also want to be able to remove a shutter that has warped and needs to be planed straight.

And something to drive it
Some pneumatic expression systems feature an individual pneumatic to operate each shutter. Each contact on the expression pedal opens one shutter. (Most Möller organs work that way.) But it’s more common for the shutters to be linked together by an action that is in turn operated by a single machine. The machines can be electro-pneumatic or all-electric. But what you’re looking for is a combination of expression machine, linkage, and shutters that have a large enough travel so the shutters can close tight and open really wide, move silently when operated either fast or slow, and that have plenty of gradation between stages so that the range of expression seems infinite.
Most electro-pneumatic or electric expression machines have eight stages. It’s generally agreed that for most organs eight-stage expression are sufficient. I think it was Ernest Skinner who built the first sixteen-stage machines. (Dear reader, if you know otherwise please share it.) Those machines are elegant, fast, and powerful. Dividing the travel of the console expression machine into sixteen stages really gives a smooth operation.
Mr. Skinner called his expression motors Whiffle-trees. The term Whiffle-tree was originally used to describe the system of harnesses and reins that tied a team of horses together, allowing the weight of the load to be distributed between the horses according to their individual strength. Mr. Skinner used that principal to harness a row of pneumatic motors together so that each motor (or stage of the machine) contributes to the motion of the shutters and collectively they equal the total motion of the machine. Skinner’s Whiffle-tree expression motors were installed in thousands of Skinner and Aeolian-Skinner organs and in my opinion set the standard for electro-pneumatic pipe organ expression.
There are several suppliers to the pipe organ industry that have developed and market all-electric expression motors. The best of these use the powerful, compact, and quiet electric motors developed for wheelchairs. They are equipped with solid-state controls that translate the contacts on the console expression pedal into stages of expression. The organbuilder can adjust them for different distances of travel and adjust the amount of travel and the speed of each stage separately. So, for example, you can make the first step from fully closed be fast on opening (so it responds instantly) and slow on closing (so it doesn’t slam shut). Mr. Skinner handled this by using a small exhaust valve for the first stage, which choked its speed, keeping the shutters from slamming.

A rose by any other name
You’ll notice that I’m saying expression box, pedal, or shutter rather than Swell box. It’s true that most organs with expression are two-manual organs, and on a two-manual organ the expressive division is usually a Swell. But keeping the language clean, I’d rather not put a Choir division in a Swell box—so expression is the word.

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In a large organ, the shutters of one division might collectively weigh close to a ton. It takes a lot of thought and skilled engineering to get that amount of stuff to move quickly and silently in response to the artistic twitch of an organist’s ankle. But when an expression chamber is working well, it can produce breathtaking effects. As familiar as I am with all that gear, I love to think of that big mass of stuff on the move when I’m sitting in the pews listening to an organ. It’s difficult to express.