out of a small plank of beech and shaped
it. The tapered cross-section is only
about half an inch in height and width.
A more interesting shape
I thought a rectangular box frame was
rather uninteresting. As the lower keys
are shorter at the left (operating area to
tangent), there is usually unnecessary
space beyond them and the hitch pins may
be far from the tangent.
Tapering the back of the frame by cutting
off the keys not far behind the tangents
resulted in a more interesting shape and
better location for the hitch pins.
At the right end, the distance from
bridge to tuning pins also results in
unnecessary length of the short strings
and soundboard, so I designed a tapered
right end for the instrument, placing the
tuning pins further in for higher notes.
With 53 pairs of strings even under
only moderate tension the stress on the
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2½-inch square wood from the piano,
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accurately as I could with a tenon saw, a
coping saw, and chisels, and glued and
secured with two large screws.
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this to avoid splitting by the tuning
pins. To support the inner edge of thesoundboard, I used a similar piece, curved
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for the quarter-inch rim all round to which
the soundboard was glued.
To carry the bulky frame along under
the keys at the front would result in
design problems, so under the guide pin
bar below the keys, I laminated a thinner
piece of hardwood. However, I needed to
increase this later.The height of the strings
It remained to calculate the height for
the strings passing over the bridge to
allow slight downward pressure on the
soundboard, but not too much, as there
are 106 strings.
Passing over the bridge, each is located
by a tiny inclined pin from where it passes
slightly backwards to keep it located, and
slightly downwards as described, to enter
the small hole in the tuning pin.I designed a tapered right
end for the instrument,
placing the tuning pins
further in for higher notesHow does a clavichord work?
The clavichord evolved as a usually
rectangular box with a basic keyboard
and strings stretching from the left
side over a bridge on a soundboard at
the right end, each string ending at a
tuning pin. The strings for the higher
notes on the keyboard are necessarily
shorter. The notes are like a simple
see-saw. Pressing the front end raises
a ‘tangent’ (short section of brass)
on the other end to touch the string
which then vibrates between tangent
and bridge.
When the key is released, the string
doesn’t sound as it is damped
with felt at the left near where it is‘hitched’. If pressure on the key is
increased, this raises tension on the
string, slightly raising the pitch so
that a vibrato effect is possible. This is
unlike any other keyboard instrument
and makes the music particularly
expressive, but it’s not loud.
Depending on the number of keys, a
clavichord might be as small as two or
as much as five feet long (60–150cm).
If it had just over four octaves it
would be about four feet long
(120cm). It could sit on a table or
a stand and was quite portable. In
almost all cases the lid of the box was
hinged to open at the back, whichwas often arranged to provide a
music rest.
The length and tension of the string
as well as its material and diameter
affect the character of the note. Steel
and thick strings make rather a hard
sound; brass is softer but quieter.
There is also the problem of tension
from many strings on a basic frame.
For this reason original instruments
often used the same string or pair of
strings for two or more notes (bunden
or ‘fretted’); those notes could not
be played simultaneously which was
an obvious limitation. Strings were
usually paired, for a better sound.