The harpsichord: an introduction, part 3
In my previous column (November 2024, page 8), I noted that this installment would be about the mechanism of the harpsichord and how that shapes touch and technique. My next installment will explore the relationship between the mechanism and performance. This is part of the “demystifying” process that I mentioned in my first column on the harpsichord (August 2024, page 8). Grappling with some of the arcana of how this type of instrument works will hopefully make it more accessible.
My friend and colleague, the late harpsichord builder Philip Tyre, once said that no harpsichord is more than a millimeter away from catastrophic mis-regulation. This sounds intimidating. But it also means that many harpsichords that seem mechanically hopeless are less than a millimeter away from being absolutely fine! This is an encouraging thought for anyone attempting to care for a harpsichord for the first time. Everything about the workings of a harpsichord is conceptually simple and based on common sense.
In a harpsichord the strings are plucked by small plectra that are held near those strings by action pieces called “jacks.” These in turn rest on the back ends of the keys. The small plectra pluck the strings going up, and when a key is released they come back down, slipping out of the way so as not to pluck the strings again. The jacks also hold the dampers, which I will explore in a bit. The jacks only rest on the keys; they are not attached to them. They come back down when the key is released because of gravity: they are not pulled down mechanically. This is an action that is much simpler and with fewer moving parts than the action of a piano or any but the very smallest mechanical-action organ.
The keys
Harpsichord keys are simple levers, see-saws, in effect (Illustration 1). When one pushes the key down in front, the back goes up. I have never known a harpsichord key to have any moving parts. One of the reasons that playing harpsichords can feel very different from one another is that details of the design of the keys can differ. The overall weight, the placement of the balance rail (the center of a see-saw, though not necessarily in the exact center of a harpsichord key), the placement of felt under, over, or on the keys at various points, and other physical features can vary a lot between instruments. At the middle of the see-saw, a pin goes through a hole in each key. The size and snugness of that pin and hole can also affect the feel.
The feel of a harpsichord action has a characteristic shape. As the key starts to descend, it does so smoothly. At a certain point the plectrum encounters the string, and there is resistance. After the string has been plucked, the key moves smoothly again. Differences in the details of the construction of the keys and jacks can affect the specifics of how the action feels from one harpsichord to the next. Sometimes most of the resistance of the key is in the plucking, and other times most of it is in the act of moving the weight of the key down, and the moment of plucking is subtle or light. Dramatic differences along these lines from one instrument to another are normal and to be expected.
This description of the feel of depressing harpsichord keys suggests similarities to the feel of playing a mechanical-action organ, where there is also a similar range of variety. Throughout history, most harpsichordists have also been organists. The feel and behavior of the action between the two instruments are similar, even though the nature of the sound is in many ways quite different. The feel and behavior of any sort of non-mechanical-action organ is quite different, as is that of a piano.
There are other very straightforward differences in the action among different harpsichords. The keys are not always the same size from one instrument to another or from one manual to another on a double-manual instrument. The width of the keys and thus how far it is from one note to another can vary. Some harpsichords have an octave span of 6½ inches, like that of a typical piano and most (though not all) organs that we encounter. Some have an octave span of 6¼ inches. These are both reasonably standard, but widths in between are found. This could be expected to make our innate kinesthetic sense of how to reach intervals or find notes a bit unreliable, at least initially. If one sits at an unfamiliar harpsichord and finds oneself playing more wrong notes than usual, this is probably the reason. Players adjust quickly to these slight differences, usually without needing to do anything focused about it. Normal, careful practice almost always does it.
Harpsichord keys are also usually shorter than piano keys or the keys of most organs. Not surprisingly, there is variety here as well. In particular, the relationship between the length of the natural keys and the length of the sharps and flats is not necessarily the same from one instrument to another. Nor is the width of the raised keys, and therefore the width of the space on the naturals between the raised keys that is available for fingers. These differences can easily suggest different fingerings even for the same player as that player goes from one instrument to another.
The dampers
In planning out what to say about harpsichord dampers, I realized that any musical instrument either does or does not require continued input from a player to keep sounding once the sound has been initiated. Most do—bowed string instruments, wind and brass instruments, the human voice, and indeed the organ. If whatever the player or singer has done to start the sound ceases to happen, the sound will cease. On harpsichord and other plucked, stringed instruments, and on at least most percussion instruments, this is not the case. Once the player has initiated the sound, that sound simply goes through its lifespan until it dies away or is ended on purpose. In the previous column I wrote about what the shape of that continued sound might be in a harpsichord. But the point here is that this is why dampers are needed. If we want harpsichord, piano, clavichord, guitar, glockenspiel, harp, or drum notes to end before they would naturally die away, we must do something about it. In some situations on plucked string instruments, we do not care about the sound being ended at a specific time. Notes are often just allowed to die away as the following notes are being played. But if a player wants a note to end, they must do something about it, presumably damping the string(s) with a hand. It is common to see tympanists do something like that.
With keyboard instruments, we need our hands for other things. So damping notes when we want them to end is part of the mechanism. On the piano, the dampers have their own rather intricate action and can be taken away from the strings by using the damper pedal. On the harpsichord, each jack has its own damper. These are positioned in such a way that when the key is at rest the damper sits on or next to the string and keeps it from vibrating, such that when the key is played the first thing that happens is the damper moves off the string, before the plectrum plucks, and that when the key is released, after the plectrum has slipped back under the string, the damper encounters the string again and stops the sound. This is one of those areas in which everything must be designed and adjusted to a very fine tolerance. If the distance between the plectrum and the damper is too great, the damper will not touch the string and will not have any effect; if that distance is too small, the damper will keep the plectrum from slipping back under the string and cause that note not to play the next time the key is pressed.
In Illustration 2, the upper section of a jack seen from the side, the black dot shows where the string would be. (We are looking directly along the length of the string.) The red damper touches the string from the side and is angled in such a way that when the jack moves up—the direction of the blue arrow—the damper will immediately move away from the string. Shortly thereafter, the white plectrum will touch and then pluck the string. On many harpsichords, it is possible to shape the sound of the ends of notes in a way that is musically meaningful and useful through controlling the speed with which the damper encounters the string and ends up resting fully on it. This I will address next time, along with other aspects of the relationships among mechanism, sonority, and touch.
When a harpsichord has two 8′ stops, the strings for those stops are arranged in pairs. The notes from each stop that share a pitch are not the two closest together, but rather the two on opposite sides of a gap. (See Illustration 3, in which the red arrows point to two strings with the same pitch as each other, and the blue arrows do likewise, to the note a semitone away.) The two sets of jacks that pluck each set of strings respectively rest on the backs of their keys, fitting into those gaps. One set of jacks faces one way and plucks one set of strings, the other set of jacks faces the other way and plucks the other set of strings. (See Illustration 4, in which I have drawn black boxes around two jacks each addressing its proper string. Outlined in blue is a jack that plays a 4′ string. The 4′ strings are below the 8′ strings—closer to the soundboard or the ground.)
Harpsichord jacks always go up and down with the playing and releasing of their keys, but they do not always pluck the string. The nature of the stop mechanism entails that each whole row of jacks can be moved very slightly from side to side so that the plectra either are or are not under the strings. If the row of jacks has been moved back, the off position, then the jacks will go up and down silently, as the plectra pass next to the strings rather than plucking them. When the row of jacks is moved into the on position, when a key is played and the jack starts to move up, the plectrum in that jack will encounter and then pluck the string. This has something in common with the action of a slider and pallet windchest in a mechanical organ. Two things must be in position for sound to be created: stop action and key. Illustrations 5 and 6 show jacks in the on and off positions, respectively.
Sound timbre
It is primarily the positioning of the jacks along the length of the strings that determines the timbre of each stop. It is easy to see from the illustrations that the jacks of each stop cannot be in the same place as one another. One set will pluck its strings closer to the end, and the other farther from the end and closer to the middle. The former position gives a reedier sound (somewhat analogous to a quintadena, as I mentioned last time), and the latter position gives a flutier, more gedeckt-like sound. If one has the opportunity to open a harpsichord and temporarily remove any jacks that are holding dampers on one string, one can then pluck that string by hand in different places along its length and hear even more pronounced differences in timbre. (It is also interesting to experiment with different plucking materials, such as fingernails and fingers themselves. Other outside materials should be used carefully and only with permission of whoever owns the instrument!)
As an aside, it would be possible in theory for an organ to have two or more stops that sound essentially identical—close enough that one could not distinguish them by ear. It is not often that we want this, but it could be done. On a harpsichord this is impossible.
To be continued.
