Bach's Inventions (2-voices) and Sinfonias (3 voices) were originally published in the
Klavierbüchlein for Wilhelm Friedemann Bach (1720). They were called "Preambles," and were
intended as instructional pieces in performance and compositional technique. Bach later revised them
and called then Inventios and Sinfonias.
The original ordering of the pieces was based on compositional or performance techniques, in the following key scheme:
Group 1: scalar subjects
The 1723 version reorders the Inventions according to key relationships, as follows: