|Anatomy of a Clavichord|
Of all the keyboard instruments, the clavichord is perhaps the oldest, and certainly the most expressive.
|“…solitary, melancholic, unspeakably delightful
instrument… He who has an aversion to revelry, fury and tumult and
whose heart delights in sweet sensations, will pass by the harpsichord and
fortepiano, and choose the clavichord.”
— Christian Friedrich Daniel Schubart, 1785.
The mechanism of the clavichord is simple in the extreme: The strings which run across the instrument from hitchpin to tuning pin are struck by tiny blades of brass called tangents. These are fixed near the far end of each key. At rest, each tangent lies only a few mm below the strings. When the musician plays a note, the key pivots like a tiny see-saw on its balance pin. The back part of the key rises, and the tangent taps the string, both exciting it into vibration and determining its speaking length at the same moment. If the player then exerts a little more pressure, the pitch can be varied somewhat while the note is still sounding. The other end of the speaking string length is always fixed by the bridge, which passes the tiny vibration of the string to the soundboard for radiation so we can hear it. There is a direct mechanical connection between the finger and the string as long as the note is sounding. As soon as the key is released, the vibrations travel backwards along the strings to the left, where they are promptly stopped by the listing cloth—this material woven between the pairs of strings also affects the stiffness of touch, but has nothing to do with muting the tone of the instrument.
Most clavichords are strung in pairs so are said to be double-strung. Yellow brass (70% Copper, 30% Zinc) is the usual stringing material, and the thickness
of the wire varies from bass to treble. Heavier red brass (90% Copper, 10% Zinc) strings, or even overspun strings might be used in the extreme bass. The smallest clavichords have fewer
pairs of strings than keys, resulting in an easy-to-tune, smaller and (because
of the lesser tension) often seemingly louder instrument. Similar to guitars and lutes,
this arrangement is called “fretting”, and a clavichord could said
to be either double- or triple-fretted, according to whether the
strings are shared in twos or threes throughout most of the compass. The light
weight and small size of fretted clavichords enable them to be taken anywhere.
Many of the surviving original small clavichords lack legs, so perhaps they
were table-top instruments, or meant to be played on one’s knees in a
stage coach or in bed. (One wag once remarked that the clavichord was the only
musical instrument that a person in one half of a double bed could play without
disturbing the person in the other half—and he might well have been right!)
|Unfretted Clavichord action
Carey Beebe demonstrating the action of the Unfretted Clavichord.
|Double-fretted Clavichord action
Carey Beebe demonstrating the action of the Double-fretted Clavichord.
|“…Every keyboardist should own a good harpsichord
and a good clavichord to enable him to play all things interchangeably.
A good clavichordist makes an accomplished harpsichordist, but not so the
The clavichord is needed for the study of good performance, and
the harpsichord to develop proper finger strength.”
— Carl Philipp Emanual Bach, 1753.
| Unfretted Clavichord after Gerlach
CAREY BEEBE • MMVIII
It is because the strings are struck at their most inefficient part that the clavichord is so sweet and gentle—it has been compared to playing the guitar by using the back of a knife on the fingerboard, and not plucking the strings with the right hand at all. The dynamic range, though, is quite extreme—all the way from ppp to perhaps mp— but what is remarkable is the variation of pitch possible by repeatedly exerting (down) and relaxing (up) slight pressure on the key after it has been played. Bebung was the term given by the Germans to this vibrato effect, although it was probably meant to be used with discretion like an ornament, and not an indiscriminate wallowing around on every single note like a badly trained singer. It is the degree of control allowed by this immediacy of touch, which is so lacking in all other keyboard instruments: In the clavichord, the finger is always in direct connection through the key and tangent to the sounding string.
|Detail of Unfretted Clavichord action|
Larger clavichords have individual pairs of strings for each note, and offer the greatest harmonic freedom: These are called Unfretted clavichords and are noble instruments which work well for the spirited music of Bach’s sons, and for much early piano music. With 61 notes (five octaves), for example, you cover all of Mozart, and believe it or not, all of Beethoven’s keyboard music to 1801.
You can make a clavichord much louder, if you really want to: Instead of striking the string right at the termination of its speaking length, a stronger blow can be delivered by fixing both ends of the string, and striking it somewhere in between. Such an instrument was invented once, and in fact it was responsible for changing the course of Western music history. We know it as the Pianoforte or just Piano for short—which is a silly name for such a loud instrument: It would be much more sensible for something which can be successfully pitted against a 110-piece modern symphony orchestra to be commonly known as the Forte!
The uprising of the piano can probably be attributed to the fact that it attempted to combine the best features of two very different keyboard instruments: Some of the expressiveness of the clavichord, at the rather more sociable volume level of the harpsichord, enabling serious use with other instruments. But that is another story. (See our Fortepiano page.)
| Clavichord by José Grabalos
Triple-fretted Clavichord, Carey Beebe • MCMXC
|Clavichord on the Nullabor|
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