← Bach · Well-Tempered Clavier
Prelude 17 in A-flat major BWV 886
Book II of the Well-Tempered Clavier. Under its figuration, this prelude is 99 chord changes across 77 bars — ranked 37 of 42 by measured difficulty (expert) in this survey. Played as block chords, it's a progression you can learn in an afternoon; the piece is that progression wearing sixteenth notes.
Practice this piece → Practice chords → Learn it section by section → Hear the harmony →
How it opens
The first changes are I7 (C) · V7/IV · IV7 · IV7 (Ab) · viio/V (F) · V · viio · V7 (Bb) — and the whole prelude keeps moving at roughly that harmonic pace.
What it leans on
Of 99 labeled changes, the harmonies that do the most work: V7 (6×), IV7 (F) (5×), ii7 (Ab) (5×), V7 (Bb) (4×), vi7 (Ab) (3×).
Free scores
- Blocked-chord reduction (MusicXML) — the harmony skeleton the player performs
- The prelude as written (MusicXML)