Clavichord
When I wrote several columns about tuning and temperament beginning in July 2009, I introduced the series with the following:
Most organists do not have to do any tuning as such, or at least can do without tuning if they prefer. However, it is very convenient indeed for any organist to be able to touch up a tuning . . . . Beyond that, however, it is very useful and enlightening for any organist to understand the role of tuning, temperament, and the nature of different intervals in the esthetics of organ and harpsichord sound and repertoire, and in the history of that repertoire.
I can say something similar about the relationship between the organist’s calling and the history, technique, and musical nature of the oldest stringed keyboard instrument—and the one that is in many ways the most mysterious as it appears in modern musical culture—namely, the clavichord. It is utterly possible to be an organist, organ student, organ teacher, organbuilder, organ tuner, organ aficionado, and so on, without ever studying or playing—or even hearing or just thinking about—the clavichord.
Organists are very often called upon to play the piano in any number of different performance situations. They are less often but not too infrequently called upon to play harpsichord. And, of course, electronic keyboard instruments are found everywhere: anyone who is a working keyboard player is likely to be asked to use them from time to time. However, I have never once heard any report of a modern-day organist being required, or even asked, to use a clavichord in a practical performance situation.
It can be illuminating for an organist to get to know something about the clavichord. This is true partly because learning or knowing anything can be illuminating. (Finding out more about trombone or hammered dulcimer or painting or dance or baseball could end up shedding light on something about organ study or organ performance.) The clavichord is also a fellow keyboard instrument, with a history going back to the very earliest days of the surviving keyboard repertoire. It is abundantly clear that organists over many centuries typically spent at least as much time playing the clavichord as they did playing the organ. If all of any given person’s experiences tend to inform one another, then everything that went on in the interlocking worlds of organbuilding, organ playing, organ improvisation, organ composition, and all other aspects of church music between some time in the early fifteenth century and some time in the eighteenth was influenced by players’ experiences with clavichord.
It can be hard to sort out or analyze in any concise way what the nature of that influence was. There are few if any contemporary written sources that discuss that issue. (“Here is how my clavichord playing influences my organ playing.”) For the purposes of this introduction, I describe the instrument itself. There are things about the construction, design, and acoustics of clavichords that are fascinating and that raise issues that feel almost philosophical to me. Next month I will discuss some of those issues, talk about some aspects of playing technique and some of my own evolving thoughts about how my own clavichord experiences have affected other things about my musical life. I will also provide a bit of a bibliography and discography.
I should mention that it has been my experience that many organists have not had much opportunity to encounter clavichords in person or to learn very much about them. When I give workshops to groups of organists about early keyboard instruments, I ask, “Who here has played harpsichord?” and usually get 80–100% percent positive response. With the same question as to clavichord, the most usual response is zero, sometimes a person or two. So I am optimistic that these couple of columns will fill a need.
Clavichord construction
The clavichord is a stringed keyboard instrument. As with every string instrument, its principal sound-producing element is a set of strings drawn tight enough to be able to vibrate at a defined pitch. And as with almost every string instrument, those strings rest on mostly wooden elements that amplify and color the sound that the strings make. Specifically, the strings rest directly on a bridge, which is sort of like a short wall, and the bridge rests on the soundboard, which is a flattish plank built in such a way as to be resonant, sort of like a wooden drum head. There are metal pins on the bridge that hold the strings in place and participate in shaping the sound. When a string is made to vibrate, it passes those vibrations through the pins to the bridge and then to the soundboard. The sound that the listener hears is the amalgam of what the string throws off into the air directly and what the pins, bridge, and soundboard create. This description fits pianos, violins, guitars, harpsichords, dulcimers, banjos, and so on.
The pitch of a note on a string instrument is determined in part by the material of the strings and in part by how tightly it is drawn. It is also determined, importantly, by the length—not the length of the whole piece of string, but by the length of the portion that is being made to vibrate. In pianos and harpsichords, among other instruments, the strings have speaking lengths that are fixed when the instrument is built. You can observe that length, as it is between two pinned bridges. String outside those bridges doesn’t vibrate. With violins and many other instruments, changing the speaking length of strings is part of the act of playing.
Most clavichords have strings in unison pairs. When I talk about making “the string” sound or determining the speaking length of “a string,” I mean the unison pair if there are such pairs or an individual string if there are not unison pairs. You can see the overall layout of a clavichord in photograph 1, and a close-up of the bridge resting on the soundboard, with pairs of strings crossing it, in photograph 2.
Each string instrument also has some way in which the strings are made to vibrate. With guitars, lutes, autoharps, and so on, the strings are plucked by hand or by a hand-held implement. With the harpsichord and its variants, the strings are plucked indirectly through a keyboard. With instruments of the violin and gamba families, the strings are made to vibrate by being rubbed with a bow, and something similar happens with a hurdy-gurdy. With hammered dulcimer and piano, the strings are struck.
This is where things get interesting as to the clavichord. Clavichord strings are made to vibrate by being struck. But whereas on a piano or with a hammered dulcimer, the device that strikes a string (the hammer) moves away from that string instantly, with the clavichord the element that strikes the string (a piece of brass called a tangent, that is found at the back of each key) remains in contact with the string until the key is released. Pretty much everything that is different or interesting about the clavichord, that which makes a clavichord a clavichord, stems directly from this setup. Here are some aspects of this:
1) When the tangent touches the string to make it vibrate, it also blocks sound waves from traveling across the spot where it touches the string.
2) This means that the speaking length of the string starts specifically where the tangent is touching it.
3) In turn, this also means that logically the tangent would seem to divide the string into two separate speaking lengths, one to its left, one to its right. It would indeed do this, except that:
4) In order to avoid the tangent’s causing two separate notes to sound, the strings to one side of the tangents are permanently damped by cloth wound between them. Only the other sides of the strings are allowed to sound, and the strings pass over a bridge and soundboard only on that side. You can see tangents, strings, and the damper cloth (known as listing cloth) in photograph 3.
5) Since the tangents define one end of the sounding string, they are also initiating the sound of the string at its very end. This is different from other stringed keyboard instruments, where the action that makes the strings sound is located some ways away from either end of the strings. You can observe this by looking inside any harpsichord or piano. On non-keyboard string instruments, the player can make choices, within a certain range, about where along the strings to initiate the sound.
6) The very end of a string is by far the least efficient place to try to make it sound; the middle is the most efficient. The loudest sound that you can try to make from the end of a string will be a lot quieter than a sound that you could get from elsewhere on the string. It is this fact, and not anything else about the construction of the instrument, that is the source of the clavichord’s overall low volume: not the bridge or soundboard design, not the size of the instrument, not the cloth wound around the strings, nothing about the shape or design of the keyboard.
Here are a couple of experiments that you can do that relate to this. If you have access to a violin or guitar or something similar, try plucking a string at the very end, either end. Then try plucking it at the middle, then elsewhere. You will easily get more volume near the middle than you can possibly get at either end. You can do the same at a harpsichord by playing and holding a note to gets its damper out of the way and then plucking that string at various points. Then try this with a clavichord: play and hold a note to get the tangent in position on its string. Then pluck that string near its middle. You will observe that you can get a lot more volume that way than you can get by actually playing that note from its key.
7) The speed or force with which a tangent touches a string is directly correlated with the volume of sound that it produces. That means that with the clavichord as with the piano you can shape the dynamics of individual notes by using different amounts of pressure or force in playing. The subtlety with which you can modulate dynamics on the clavichord is in every way equal to the same on the piano. The dynamic range is much, much narrower, going from “nearly inaudible” to something that might be called “mezzo piano.” The upper volume limit varies from one clavichord to another, but is always determined by #6 above.
8) The tangents in striking the strings can also distend them enough to change their pitch. If you play a note on a clavichord first gently and then very hard, you will sometimes notice that the latter is a bit higher in pitch than the former, or that the pitch wavers or seems unsettled. This varies from one clavichord to another, but it can place limits on the effectiveness of varied dynamics or on the useful dynamic range of a particular clavichord.
9) On a brighter note, this same attribute can be used to create a musical effect that is surprising for a keyboard instrument, namely a sort of vibrato. If after you play a note, while you are holding it, you vary the pressure on the key, the pitch will waver. Next month, I will talk about this as an interpretive/expressive effect, and about how to execute it.
10) As you release a note on a clavichord, the sound waves try to go out across the entire length of the string. In doing so they meet the cloth that has been wound around the strings for the main purpose of keeping the left-hand side of each string from sounding, as point 4 explains above. This cloth immediately damps the sound. Whereas on every other keyboard instrument the dampers descend on the strings to cause them to stop sounding, with the clavichord the dampers are already lying in wait, and the sound goes to meet them.
11) Since the speaking length of a clavichord string is determined by the placement of the tangent, it follows that the same string can be made to play more than one different note. If you place tangents at different points along the length of a string, each of those tangents will define a different end-point for the speaking length of that string, and therefore make a different pitch. In theory, there is no reason that you couldn’t get all of the notes across the whole compass of an instrument from a total of one string, each note made by a tangent at the back of its key, at the right place on the string to create the correct pitch for that note. An instrument set up like this could only play one note at a time and would be of limited relevance to playing what we think of as the keyboard repertoire.
However:
12) It is, by extension, also possible to group several adjacent notes, short of the entire compass of the instrument, onto the same string by placing their tangents all on that string, in the correct alignment to produce the desired pitches. This was extremely common in clavichord design from the very earliest days through the early to mid-eighteenth century. Some of the earliest clavichords have some or all of their notes sharing strings in groups of four, perhaps E-flat, E, F, F-sharp.
Later, well into the eighteenth century, it was common for certain notes to be grouped in pairs, with, for example, C and C-sharp, E-flat and E, F and F-sharp, G and G-sharp, and B-flat and B sharing strings. This was musically acceptable because it was not considered necessary to write or improvise music in which those adjacent semitones were played together. (If you play two adjacent keys whose notes share a string together, you hear the higher note, plus an odd clicking noise.) It is entirely possible to play the two notes that share a string in very quick succession, even to trill on them.
You can see pairs of tangents addressing different places on the same strings in photograph 4. Reading left to right tangents 1 and 2, 3 and 4, and 6 and 7 are in pairs. Tangent 5 is alone on its pair of strings. The first two play F and F-sharp, the next two play G and G-sharp, the next one plays A, and the last two play B-flat and B.
A clavichord on which some notes are grouped in pairs or larger units sharing strings is called a fretted clavichord. A clavichord on which every note has its own string or pair of strings is called an unfretted clavichord. Unfretted clavichords only became common in the mid-eighteenth century.
To be continued . . .
