Jazz blues · C major
This is the 12-bar jazz blues form with the ♯iv°7, VI7 and ii–V turnaround that jazz players add to the plain blues — in C, the chords are C7 – F7 – F♯°7 – A7 – Dm7 – G7. In C the blues is C7, F7 and G7 at heart; jazz players add F♯°7 in bar 6 (bass F♯ climbing back to C), A7 in bar 8 to set up the Dm7 – G7 cadence, and a C7 A7 | Dm7 G7 turnaround in the last two bars.
The form
12-bar chorus
Generic form in Roman numerals — the harmonic skeleton, not any particular tune. Two chords in a bar are two beats each.
Interactive trainer
Piano · C7 with Mixolydian
Guitar · standard tuning
Piano · F7 with Mixolydian
Guitar · standard tuning
Piano · F♯°7 with Diminished (whole–half)
Guitar · standard tuning
Piano · A7 with Mixolydian
Guitar · standard tuning
Piano · Dm7 with Dorian
Guitar · standard tuning
Piano · G7 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 |
|---|---|---|---|---|
| I⁷ | C7 | C – E – G – B♭ | Mixolydian | C D E F G A B♭ |
| IV⁷ | F7 | F – A – C – E♭ | Mixolydian | F G A B♭ C D E♭ |
| ♯iv°⁷ | F♯°7 | F♯ – A – C – E♭ | Diminished (whole–half) | F♯ G♯ A B C D D♯ F |
| VI⁷ | A7 | A – C♯ – E – G | Mixolydian | A B C♯ D E F♯ G |
| ii⁷ | Dm7 | D – F – A – C | Dorian | D E F G A B C |
| V⁷ | G7 | G – B – D – F | Mixolydian | G A B C D E F |
| Guide tones | C7 | F7 | F♯°7 | A7 | Dm7 | G7 |
|---|---|---|---|---|---|---|
| 3rd | E | A | A | C♯ | F | B |
| 7th | B♭ | E♭ | E♭ | G | C | F |
How to practise this
1. Arpeggios in time. Loop the vamp at 70–90 bpm and play C7, F7, F♯°7, A7, Dm7, G7 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: E–B♭ → A–E♭ → A–E♭ → C♯–G → F–C → B–F. Notice that F, the 7th of G7, falls a half-step to E, the 3rd of C7 — that is the resolution.
3. Chord-scales. Run Mixolydian on C7, Mixolydian on F7, Diminished (whole–half) on F♯°7, Mixolydian on A7, Dorian on Dm7, Mixolydian on G7, then improvise keeping chord tones on beats 1 and 3.
4. Move it. When C is clean, go to F major — a fourth up — and keep going around the circle.
Common questions
C7 – F7 – F♯°7 – A7 – Dm7 – G7. The I7 chord is C7 (C, E, G, B♭); The IV7 chord is F7 (F, A, C, E♭); The ♯iv° chord is F♯°7 (F♯, A, C, E♭); The VI7 chord is A7 (A, C♯, E, G); The ii chord is Dm7 (D, F, A, C); The V chord is G7 (G, B, D, F).
C7: Mixolydian (C D E F G A B♭). F7: Mixolydian (F G A B♭ C D E♭). F♯°7: Diminished (whole–half) (F♯ G♯ A B C D D♯ F). A7: Mixolydian (A B C♯ D E F♯ G). Dm7: Dorian (D E F G A B C). G7: Mixolydian (G A B C D E F).
The thirds and sevenths: E and B♭ over C7, A and E♭ over F7, A and E♭ over F♯°7, C♯ and G over A7, F and C over Dm7, B and F over G7. 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 C: ii–V–I · turnaround · rhythm changes. Read the theory in Chord-scale theory, or see the scales on their own pages: C Mixolydian, F Mixolydian, F♯ Dim. W–H, A Mixolydian, D Dorian, G Mixolydian.