Rhythm changes · B♭ major
This is the 32-bar AABA rhythm-changes form — here the 8-bar A section and the dominant-cycle bridge — in B♭, the chords are B♭△7 – Gm7 – Cm7 – F7 – B♭7 – E♭△7 – E°7 – D7 – G7 – C7. In B♭ the A section walks B♭△7 – Gm7 – Cm7 – F7 twice, then pushes to the IV chord E♭△7 through B♭7; the passing E°7 lifts the bass from E♭ to F. The bridge is a chain of dominants a fourth apart — D7 → G7 → C7 → F7 — two bars each, landing back on B♭△7.
The form
A section (8 bars)
Bridge (8 bars)
Generic form in Roman numerals — the harmonic skeleton, not any particular tune. Two chords in a bar are two beats each.
Interactive trainer
Piano · B♭△7 with Major (Ionian)
Guitar · standard tuning
Piano · Gm7 with Dorian
Guitar · standard tuning
Piano · Cm7 with Dorian
Guitar · standard tuning
Piano · F7 with Mixolydian
Guitar · standard tuning
Piano · B♭7 with Mixolydian
Guitar · standard tuning
Piano · E♭△7 with Major (Ionian)
Guitar · standard tuning
Piano · E°7 with Diminished (whole–half)
Guitar · standard tuning
Piano · D7 with Mixolydian
Guitar · standard tuning
Piano · G7 with Mixolydian
Guitar · standard tuning
Piano · C7 with Mixolydian
Guitar · standard tuning
Click any chord card to see its scale, and tap any key or fret to hear that note. Turn on “+ Arpeggios” or “+ Scales” and the guitar or piano plays the line live over the vamp, lighting each note on the diagram as it sounds. All audio is synthesized in your browser — nothing is recorded or copyrighted.
Reference
| Function | Chord | Chord tones (1–3–5–7) | Chord-scale | Scale notes |
|---|---|---|---|---|
| I△ | B♭△7 | B♭ – D – F – A | Major (Ionian) | B♭ C D E♭ F G A |
| vi⁷ | Gm7 | G – B♭ – D – F | Dorian | G A B♭ C D E F |
| ii⁷ | Cm7 | C – E♭ – G – B♭ | Dorian | C D E♭ F G A B♭ |
| V⁷ | F7 | F – A – C – E♭ | Mixolydian | F G A B♭ C D E♭ |
| I⁷ | B♭7 | B♭ – D – F – A♭ | Mixolydian | B♭ C D E♭ F G A♭ |
| IV△ | E♭△7 | E♭ – G – B♭ – D | Major (Ionian) | E♭ F G A♭ B♭ C D |
| ♯iv°⁷ | E°7 | E – G – B♭ – D♭ | Diminished (whole–half) | E G♭ G A B♭ C D♭ E♭ |
| III⁷ | D7 | D – F♯ – A – C | Mixolydian | D E F♯ G A B C |
| VI⁷ | G7 | G – B – D – F | Mixolydian | G A B C D E F |
| II⁷ | C7 | C – E – G – B♭ | Mixolydian | C D E F G A B♭ |
| Guide tones | B♭△7 | Gm7 | Cm7 | F7 | B♭7 | E♭△7 | E°7 | D7 | G7 | C7 |
|---|---|---|---|---|---|---|---|---|---|---|
| 3rd | D | B♭ | E♭ | A | D | G | G | F♯ | B | E |
| 7th | A | F | B♭ | E♭ | A♭ | D | D♭ | C | F | B♭ |
How to practise this
1. Arpeggios in time. Loop the vamp at 70–90 bpm and play B♭△7, Gm7, Cm7, F7, B♭7, E♭△7, E°7, D7, G7, C7 as 1–3–5–7 quarter notes, one chord per bar. Use the “+ Arpeggios” loop above to hear it played and copy the line.
2. Guide tones. Play only the 3rd and 7th of each chord: D–A → B♭–F → E♭–B♭ → A–E♭ → D–A♭ → G–D → G–D♭ → F♯–C → B–F → E–B♭. Notice that E♭, the 7th of F7, falls a half-step to D, the 3rd of B♭△7 — that is the resolution.
3. Chord-scales. Run Major (Ionian) on B♭△7, Dorian on Gm7, Dorian on Cm7, Mixolydian on F7, Mixolydian on B♭7, Major (Ionian) on E♭△7, Diminished (whole–half) on E°7, Mixolydian on D7, Mixolydian on G7, Mixolydian on C7, then improvise keeping chord tones on beats 1 and 3.
4. Move it. When B♭ is clean, go to E♭ major — a fourth up — and keep going around the circle.
Common questions
B♭△7 – Gm7 – Cm7 – F7 – B♭7 – E♭△7 – E°7 – D7 – G7 – C7. The I chord is B♭△7 (B♭, D, F, A); The vi chord is Gm7 (G, B♭, D, F); The ii chord is Cm7 (C, E♭, G, B♭); The V chord is F7 (F, A, C, E♭); The I7 chord is B♭7 (B♭, D, F, A♭); The IV chord is E♭△7 (E♭, G, B♭, D); The ♯iv° chord is E°7 (E, G, B♭, D♭); The III7 chord is D7 (D, F♯, A, C); The VI7 chord is G7 (G, B, D, F); The II7 chord is C7 (C, E, G, B♭).
B♭△7: Major (Ionian) (B♭ C D E♭ F G A). Gm7: Dorian (G A B♭ C D E F). Cm7: Dorian (C D E♭ F G A B♭). F7: Mixolydian (F G A B♭ C D E♭). B♭7: Mixolydian (B♭ C D E♭ F G A♭). E♭△7: Major (Ionian) (E♭ F G A♭ B♭ C D). E°7: Diminished (whole–half) (E G♭ G A B♭ C D♭ E♭). D7: Mixolydian (D E F♯ G A B C). G7: Mixolydian (G A B C D E F). C7: Mixolydian (C D E F G A B♭).
The thirds and sevenths: D and A over B♭△7, B♭ and F over Gm7, E♭ and B♭ over Cm7, A and E♭ over F7, D and A♭ over B♭7, G and D over E♭△7, G and D♭ over E°7, F♯ and C over D7, B and F over G7, E and B♭ over C7. Each voice moves by a half-step or stays put — that is what makes the progression sound like it resolves.
Loop the vamp at a slow tempo, play each arpeggio 1–3–5–7 in time, then play each chord-scale up and down, then improvise using only chord tones on the strong beats. When it is clean, move to the next key around the circle of fourths.
All twelve keys
Related in B♭: ii–V–I · turnaround · jazz blues. Read the theory in What is a ii–V–I?, or see the scales on their own pages: B♭ Major, G Dorian, C Dorian, F Mixolydian, B♭ Mixolydian, E♭ Major, E Dim. W–H, D Mixolydian, G Mixolydian, C Mixolydian.