The four-voice fugue, marked = 84, is 58 measures long, unusually lengthy, and one of the most deeply conceived in the collection. The subject resembles a figured chorale theme, consisting of ten chromatic quarter notes spanning an octave over three measures, progressing from the dominant to the tonic. With the entry of the answer, which introduces F-sharp and E-flat, all twelve notes of the chromatic scale are presented. This use of the complete chromatic scale is highly unusual and comparable only to the subject of the
24th fugue in the collection. \version "2.18.2" \header { tagline = ##f } \score { \new Staff \with { } > \layout { \context { \Score \remove "Metronome_mark_engraver" %\override SpacingSpanner.common-shortest-duration = #(ly:make-moment 1/2) } } \midi {} } Two countersubjects follow shortly after the subject and are systematically combined with it in regular inversion. The first countersubject, introduced in measure 4, contrasts with the subject through its division into four fragments and its octave range. This figure, often referred to as "sighs", recurs throughout the piece. The downward octave leap appears only in the
exposition and is not sustained in subsequent entries. \version "2.18.2" \header { tagline = ##f } \score { \new Staff \with { \remove "Time_signature_engraver" } > \layout { \context { \Score \remove "Metronome_mark_engraver" %\override SpacingSpanner.common-shortest-duration = #(ly:make-moment 1/2) } } \midi {} } The second countersubject, introduced at the end of measure 7, complements the first and contributes to a texture characterized by dissonance and severity. Although the fugue is constructed using invertible counterpoint, not all combinations of the subject and countersubjects are employed. The episodes, or "bridges," are also treated with flexibility; the first two (measures 10–13 and 16–19) serve as the basis for the remaining episodes (five in total), except for the passage from measures 37 to 40, which is derived from the material of the first countersubject. The
dactylic rhythmic motif is derived from the first
bridge connecting the subject and the first countersubject. Commonly used in Bach's cantatas, this rhythmic figure was referred to by
Albert Schweitzer as the "motif of joy". In this context, however, it conveys a sense of serenity and inner calm. \version "2.18.2" \header { tagline = ##f } \score { \new Staff \with { \remove "Time_signature_engraver" } > } >> \layout { \context { \Score \remove "Metronome_mark_engraver" \override SpacingSpanner.common-shortest-duration = #(ly:make-moment 1/2) } } \midi {} } == Relationship ==