Bach’s keyboard works were written for the pipe organ, harpsichord, pedal harpsichord
and clavichord. Bach was not very impressed with the early pianos produced by
Gottfried Silbermann as he considered that the treble sound was too weak. He did
approve of later models but it seems that he never wrote for the piano. Bach wrote many
of his keyboard compositions for the pipe organ or the pedal harpsichord and he wrote his
Italian Concerto specifically for a two manual harpsichord. Bach otherwise wrote for the
harpsichord and clavichord.
The clavichord, which is a much older and simpler instrument, was portable and was the
ordinary instrument of domestic music making. The clavichord had a very soft, gentle
tone and was not suitable for public music making. It did have the advantage that it could
produce dynamic nuances within a small scale.
The harpsichord was the instrument of public music making, usually accompanying
string instruments. Harpsichord tone lacked dynamic nuance because the string was
plucked mechanically, but the best examples had a splendid sound. The harpsichord was
a much more complex and expensive instrument than the clavichord and would have
been owned mainly by the wealthy classes and comfortably off musicians.
Some of Bach’s compositions such as his Chromatic Fantasia and Fugue and his Italian
Concerto were obviously written for a two manual harpsichord. Apart from compositions
such as these, to go through Bach’s keyboard works trying to decide which were written
for harpsichord and which were written for clavichord will tend to be inconclusive. It
may also be futile as the division between the two instruments did not on the whole work
that way.
Works
Many of Bach’s keyboard works are anthologies that encompass whole theoretical
systems in an encyclopaedic fashion.
The Well Tempered Clavier Books 1 and 2 BWV 846-893 each consist of a prelude and
fugue in each of the 24 major and minor keys.
The Inventions and Sinfonias BWV 772-801 consist of two and three part inventions,
respectively. These contrapuntal works are arranged in order of key signatures of
increasing sharps and flats, omitting some of the lesser used ones. The pieces were
intended by Bach for instructional purposes.
The English Suites BWV 806-811, the French Suites BWV 812-817 and the Partitas for
Keyboard BWV 825-830 each contain six suites built on the standard model of allemande,
courante, sarabande, [optional movement] and gigue. The English Suites closely follow
the traditional model, adding a prelude before the allemande, and including a single
movement between the sarabande and the gigue. The French Suites omit preludes, but
have multiple movements between the sarabande and the gigue. The Partitas expand the
model further with elaborate introductory movements and miscellaneous movements.