Blues to jazz · step 4 of 5

Minor blues: the chord progression and a backing track

Same twelve bars, minor colour. For a blues player it is the most familiar jazz form of all: B.B. King’s The Thrill Is Gone is a minor blues with the same move in bars 9–10 that John Coltrane used in Mr. P.C. and Equinox.

Your key

1Cm7Im7

2Fm7IVm7

3Cm7Im7

4Cm7Im7

5Fm7IVm7

6Fm7IVm7

7Cm7Im7

8Cm7Im7

9A♭7♭VI7

10G7altV7alt

11Cm7Im7

12Dm7♭5IIøG7altV7alt

New in this step

▶ Play it in JamShed

Tempo

Swing · 144 bpm · Cm · the trio repeats the form until you stop it

What changed

The I and the IV are minor sevenths, and bars 9–10 replace V–IV with ♭VI7–V7alt (in C minor, A♭7 to G7alt): a dominant a semitone above the V, sliding down into it. Bar 12 turns the form around with the minor ii–V, IIø–V7alt (Dm7♭5–G7alt).

Wayne Shorter’s Footprints stretches the same idea to twenty-four bars in 3/4. Here the trio swings in 4/4; if you want it closer to The Thrill Is Gone, switch the style in JamShed to even 8ths.

Your pentatonic box here (in C minor)

Here the minor pentatonic is not a borrowed sound, it is the key: C minor pentatonic (C E♭ F G B♭) is inside over Cm7, and over Fm7 it gives the 5th, ♭7, root, 9th and 11th — all good notes.
A♭7 in bar 9 is where it breaks, on one note: the G of your box is the major seventh of A♭7. Move it down a fret to G♭, the ♭7, and the box fits again.
G7alt in bar 10: E♭, F and B♭ of your box are the ♭13, the ♭7 and the ♯9 — exactly the altered sound. Only the C rubs, against B, the third. Move it a fret down and the bar is yours.
For a more modern colour over G7alt, D♭ major pentatonic (D♭ E♭ F A♭ B♭) is almost the whole altered scale. The pentatonics finder shows why, note by note.

The tips are in the step’s own key; in another key the same degrees apply. The pentatonics finder shows any pentatonic against any chord, note by note.

How to practise this step

Loop bars 9–10 and play the box with the two changes: G♭ instead of G on A♭7, B instead of C on G7alt.
Then the whole form, resolving every G7alt onto E♭ or G of Cm7.
When the 4/4 feels at home, open Footprints and play the same idea in 3/4.