Prelude and Fugue in B-flat major
About this arrangement
This is No. 21 in Book 1 of the Well-Tempered Clavier, compiled in 1722 in Köthen. The prelude is 20 bars in two 10-bar halves: the first is toccata-like, with fast broken chords and scales, and the second is more like a fantasia. In the fugue the second voice enters on the dominant in bar 5 and the third in bar 9.
Play the prelude's fast broken chords in small groups, hands separately, at 50%. In the fugue, learn the subject alone, then find the entries in bars 1, 5 and 9. Practise voice pairs, then put the three voices together.
Start with short loops.
Use the section list as a practice map. Start at 50% tempo, loop one section, then return to the full piece once the hand shape feels stable.
Choose Right or Left to focus on one hand. Wait for note checks the highlighted notes as you play them on the screen or a connected MIDI keyboard.
Before you practice.
01 How hard is Bach's Prelude and Fugue in B-flat major, BWV 866?
Advanced. The prelude is fast and needs an even touch, and the fugue is long at 48 bars with three voices.
02 How long is BWV 866?
Our score has 68 bars in total: the prelude is 20 bars in 4/4 and the fugue is 48 bars in 3/4.
03 What should I practise first?
Start with the prelude, one 10-bar half at a time. Then learn the fugue subject on its own and add voices one by one.
04 How is the prelude built?
It is two 10-bar periods. The first is toccata-style with broken chords and scale passages. The second alternates chords and scales and is closer to a fantasia.