Das Wohltemperierte Clavier I, Fuga XVII

Description

A graceful subject in A-flat major, a key of four flats, puts the hands on a layout heavy with black keys in this four-voice fugue. It is No. 17 of Book I of The Well-Tempered Clavier, the 1722 book of preludes and fugues that works through every key, sharps and flats alike.

It is a four-voice fugue in A-flat major and 4/4. An elegant, flowing subject travels through the four voices, creating a sound of settled brightness. With 884 notes in 144 seconds the note count is somewhat modest for its length, and the range, C2 to C6, fits on a 61-key keyboard. Because the key uses so many black keys, its fingering is built quite differently from keys centred on the white keys.

It is rated advanced. Besides the skill of keeping four voices distinct, it asks you to get used to hand positions in a key heavy with black keys. Making the graceful subject sing with the same expression in every voice is another key task. Lower the playback speed to check the key signature and accidentals in the score view, and sort out the four voices with the hand colours. Repeat with an A-B loop any spot where the fingering is hard to settle, and bring the speed back once you have found fingering that keeps the line flowing.

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