Prelude in B minor no. 24, BWV 869/1

The Prelude and Fugue in B minor, BWV 869 is the 24th and final pair of preludes and fugues from the first book of The Well-Tempered Clavier by Johann Sebastian Bach, compiled around 1722.

To crown his work, the composer places a grand-scale diptych capable of showcasing his contrapuntal art and musically demonstrating that all keys can be played on a keyboard thanks to a tempered tuning.

The prelude is a trio sonata movement in three voices of Corellian design, evoking a prayer. The four-voice fugue is an immense meditation with the gravity of other works such as the Passions. The entire piece is cited as an example by Kirnberger in his treatise on harmony published in 1773. It has been the subject of various transcriptions for string quartet and quintet or for orchestra.

The two books of The Well-Tempered Clavier are regarded as a benchmark by numerous composers and pedagogues. First copied by musicians, then published in the early 19th century, they serve, in addition to the music lover's pleasure, as material for studying keyboard practice and the art of composition since the 18th century.