Rhythm changes
Music theory · Jazz harmony · Level 5 · 12 min
After the blues, the most played chord progression in jazz is Rhythm Changes: the chords of George Gershwin's “I Got Rhythm” (1930). The bebop musicians of the 1940s — Charlie Parker, Dizzy Gillespie, Thelonious Monk, Bud Powell — wrote dozens of new melodies over these chords (known as contrafacts). Chord progressions belong to no one: this one is common property of jazz.
The 32-bar AABA form
Four 8-bar sections, in B♭ major (the traditional key):
| Section | Chords (2 per bar) |
|---|---|
| A (×2, and after the bridge) | | B♭ G7 | Cm7 F7 | B♭ G7 | Cm7 F7 | B♭ B♭7 | E♭ E°7 | B♭/F F7 | B♭ (Cm7 F7) | |
| B (the bridge) | | D7 | D7 | G7 | G7 | C7 | C7 | F7 | F7 | |
- The A sections cycle through the I – VI – ii – V turnaround, then visit IV (E♭) with a chromatic rise E♭ → E° → B♭/F.
- The bridge (B) is a chain of secondary dominants going round the circle of fifths: III7 – VI7 – II7 – V7, two bars each, landing back on B♭.
The first four bars, with the guide tones descending chromatically:
M:4/4
L:1/4
%%staves {RH LH}
V:RH clef=treble
V:LH clef=bass
K:Bb
[V:RH] "Bbmaj7"[DA]2 "G7"[=B,F]2 | "Cm7"[B,E]2 "F7"[A,E]2 | "Bbmaj7"[A,D]2 "G7"[=B,F]2 | "Cm7"[B,E]2 "F7"[A,E]2 |]
[V:LH] B,,2 G,,2 | C,2 F,,2 | B,,2 G,,2 | C,2 F,,2 |]
Strategy: the A sections fly by (two chords per bar, often above 200 bpm). Don't try to “play every chord”: think B♭ major with checkpoints (the B♮ of G7, the A of F7). On the bridge, by contrast, each dominant lasts two bars: take care of the guide tones (F♯ → F, B → B♭…).
The form trap: don't get lost between A and B. Learn to hear the bridge arriving (D7, with its bright F♯): it's your main landmark.