Das Wohltemperierte Clavier I, Praeludium II

Description

After the calm broken chords of the C major first prelude, this C minor prelude keeps the same tonic note but turns tense, with figuration that never stops running. It is the second piece of Book I of The Well-Tempered Clavier.

In 4/4, each hand repeats the same sixteenth-note pattern while the harmony shifts little by little, an étude-like texture. Near the end the score carries the markings Presto, Adagio and Allegro: the music suddenly speeds up, then passes through improvisatory passagework before closing. Its range runs from C2 to A-flat 5, within a 61-key keyboard.

It is rated advanced because of its density, 1,090 notes in about 1 minute 21 seconds. The task is to keep the sixteenths even in both hands and the beat steady without rushing, and to handle the late tempo changes without losing the line of the harmony. Start with slower playback to see how the two hands' patterns interlock, and use an A-B loop to isolate the section from the Presto onward; the ending then comes together much more readily.

Bach's collection of preludes and fugues for keyboard, covering all 24 keys and regarded as the summit of contrapuntal writing.