G minor, 4/4 time.

It possesses a sorrowful character, underscored by a chromatic descent of a fourth.

In the Baroque era, the essence and purpose of music were understood to lie in the expression and evocation of "Affekt." This referred not to individual "emotions" as conceived today, but rather to typified and objectified states such as "joy," "sorrow," and "suffering." The countersubject played by the lower voice at the beginning has a chromatic scale descending over the range of a fourth (G–F#–F–E–Eb–D) as its core, which is a conventional means of expressing the Affekt of "sorrow" (known as "passus duriusculus"). This contrapuntal melody, based on the chromatic scale, consistently appears in combination with the subject.

The piece is structured in two parts, with the latter half beginning from measure 11. In both halves, sixteenth notes resonate in one of the voices, designed to flow continuously throughout the entire piece.