Prelude and Fugue in A minor, BWV 543 (an alternate version is numbered BWV 543a) is a piece of organ music written by Johann Sebastian Bach sometime around his years as court organist to the Duke of Saxe-Weimar (1708–1717). It is the final incarnation of Bach's harpsichord Fugue in A minor, BWV 944, written in 1708.

Score

Prelude

The musical materials of the prelude are a descending chromatic bassline and simple arpeggiated chords above it; this is first stated solo in the manual, and, after a lengthy embellishment of a tonic pedal point, in the pedal. The highly embellished cadence that follows—full of manual runs over sustained pedal notes—leads into a contrapuntal exploration of the opening material in sequence; this is followed by a very free peroration. The Toccata-like prelude—in the stylus phantasticus—bears the marks of Bach's early, north German-influenced style, while the fugue could be considered a later product of Bach's maturity.

This is the first page of the Prelude BWV 543a

Fugue

The fugue is in 6/8 time, unlike the prelude, which is in 4/4 time. The fugue theme, like that of the prelude, is composed of arpeggiated chords and downward sequences, especially in its later half. Due to the sequential nature of the subject, the majority of the fugue is composed of sequences or cadences. The Fugue ends in one of Bach's most toccata-like, virtuosic cadenzas in the harmonic minor. Unlike most of Bach's minor-key keyboard works, it ends on a minor chord rather than a picardy third.

Liszt's transcription

Because of the piece's overall rhapsodic nature, many organists play this piece freely, and in a variety of tempi; it can be easily transcribed to a different instrument. Liszt included it in his transcriptions of the "six great preludes and fugues" BWV 543-8 for piano.

The Sicilian Clan

Italian composer Ennio Morricone created a variation of Prelude and Fugue in A minor for the main theme of the French movie The Sicilian Clan.