Prelude in C major (BWV 846, Well-Tempered Clavier Book 1)

Background

This is the first piece in Book 1 of The Well-Tempered Clavier, which Johann Sebastian Bach completed in 1722: a prelude and a fugue in each of the 24 major and minor keys, starting with C major. The title refers to a way of tuning a keyboard so that every key sounds usable. A second book of 24 followed in the early 1740s.

An earlier, shorter version of this prelude survives in the Clavier-Büchlein, the little keyboard book Bach began in 1720 for his eldest son, Wilhelm Friedemann. That origin suits it: it is a study in moving smoothly from one chord to the next, written for a learner.

In the 1850s the French composer Charles Gounod wrote a flowing melody to be sung or played over Bach's prelude, and this became his famous Ave Maria. In the nineteenth century some editions also inserted an extra bar that Bach never wrote; modern editions, and this version, keep Bach's 35 bars.

How to practise it

Nearly every bar uses the same pattern. The left hand plays two notes and holds them, the right hand plays three notes, and the right-hand notes repeat, all in sixteenth notes. Each half bar is one statement of the pattern, so each bar is one chord played twice.

Learn it first as a chain of chords. Play every bar as one five-note block chord and move slowly from chord to chord, noticing which fingers stay put and which move only one key. When the chords flow, open each one into the pattern.

The fingering shown is a good default: left hand 5 and 2, right hand 1, 2 and 4 (or 1, 3 and 5 when the chord is wider). Write in any changes you make so you play the same fingers each time.

Three places need extra care:

• Bars 22 and 23 bring tense chords with several black keys. Practise them as block chords until you can find them without looking.
• From bar 24 to bar 31 the left hand keeps returning to a low G. This held bass note builds tension, so let the music grow slightly towards bar 31.
• Bars 33 and 34 break the pattern: the right hand sweeps up and back down in a new shape over a low C. Learn them separately, then join them to the final chord.

Tempo ladder: block chords first, then the pattern at 40, 52 and the full 66 beats a minute. Hold the left-hand notes with your fingers for their full length rather than relying on the pedal, and keep every sixteenth note the same loudness, so the harmony does the work.

For more on slow, section-by-section work, see how to practise piano.