B-flat major, 4/4 time.

Written in a fugato style, the piece consists of a first half (first exposition: from m. 1; second exposition: from m. 7) and a second half (third exposition: from m. 12; fourth exposition: from m. 15).

A characteristic feature of this piece is the frequent use of stretto. Stretto refers to a technique where the next subject enters before the previous one is completed, creating an overlap. It can already be observed in measures 3 and 6, where the lower voice enters in a cascading manner against the upper voice. While these instances occur in the episodes, stretto of the subject itself is found in the latter half.

In the latter half, the middle voice forms a stretto against the upper voice, first delayed by one beat from m. 12, and then by a half beat from m. 17. From m. 20, which marks the final subject statement, all three voices (middle voice → upper voice → lower voice) present the subject in stretto, forming the climax of the piece.