C minor, 4/4 time.

For this piece's "inventio (conception)," a theme employing canonic technique was devised. It is noteworthy as the only canonic keyboard work composed before the Goldberg Variations (BWV 988).

The entire piece is divided into three sections. First, in the initial theme exposition, the lower voice follows the upper voice with a two-measure delay (mm. 1-10). In the subsequent ten measures, the lower voice repeats the material of the upper voice from the first exposition in the dominant key of G minor, with the upper voice then following it. Thus, in the second exposition, the same structure as the first exposition is maintained, but with voice inversion (mm. 11-20). The final seven measures are not canonic; after a two-measure introduction, they form a coda through imitation of the theme.