The Prelude and Fugue in B-flat minor, BWV 891, is a keyboard composition by Johann Sebastian Bach.
It is the 22nd prelude and fugue in the second book of The Well-Tempered Clavier (WTC), a series of 48 preludes and fugues by the composer.
[1] The prelude is in cut time and has 83 measures.
[2] The fugue is in 32 time and has 101 measures and four voices.
[4] This article about a classical composition is a stub.