The Prelude in B minor (J. S. Bach, arranged Siloti) is an arrangement for piano by Alexander Siloti of the Prelude in E minor BWV 855a by Johann Sebastian Bach from his Klavierbüchlein für Wilhelm Friedemann Bach.
This transcription has been described as "perhaps Siloti's most tender and perfect" transcription. It transposes Bach's original down from the original E minor into B minor, and the steady sixteenth note figuration that was originally given by Bach to the left hand is changed to the right hand. Siloti does not add a repeat of the entire work in the score, yet pianists, e.g. Emil Gilels, introduces a repeat in order to allow for a change of voicing where the melody in the left hand is emphasized. The chords in the left hand are arpeggiated; however according to Siloti's daughter Kyriena (to whom the work was dedicated, he would omit the arpeggiation on the first pass and restore it on the repeat in order to heighten the effect of the left-hand melody.