Overview

The exact year of composition and the circumstances surrounding it are unclear. In a surviving manuscript in Berlin, BWV 870a is inscribed following BWV 899-902, and the New Bach Edition treats these five pieces as a single group. Some of these were revised and included in The Well-Tempered Clavier, Book II, but it is possible that the entire set was originally conceived under the idea of some kind of tonal cycle. This is because the keys from C major to G major are arranged almost sequentially in this source. In any case, they are considered educational works. Each fugue is relatively small in scale but is accompanied by a cantabile prelude.

• Prelude and Fughetta in D minor, BWV 899
  The fughetta features a subject not bound by four harmonies, which is effectively employed through counterpoint. Although called a "fughetta" due to its small scale, its content is a fine work comparable to a fugue.
• Prelude and Fugue in E minor, BWV 900
  The fughetta has a highly ornamental and brilliant subject, but there is a theory that treats it as a spurious work.
• Prelude and Fugue in F major, BWV 901
  The fugue was transposed, revised, and significantly expanded into A-flat major, and included as No. 17 (BWV 886) in The Well-Tempered Clavier, Book II.
• Prelude and Fughetta in G major, BWV 902
  The fughetta was revised and included in The Well-Tempered Clavier, Book II. The prelude exists in two versions of different lengths: the shorter BWV 902/1a and the nearly twice as long BWV 902/1. However, the shorter 1a seems to fit the fughetta of BWV 902/2 better. In The Well-Tempered Clavier, an entirely new prelude was written for the revised fugue.
• Prelude and Fugue in C major, BWV 870a
  An early version of No. 1 in C major from The Well-Tempered Clavier, Book II.