From blues to jazz, in five steps

You already have half of it

The blues is not the step before jazz. It is inside it: Charlie Parker, Thelonious Monk, Wes Montgomery and John Coltrane all recorded blues after blues, and the jazz blues of step 3 is the form a jam session falls back on when nobody knows the same tune.

What a blues player brings — time, phrasing, the blue note, knowing when to leave space — is what many jazz students take years to find. What jazz adds is chords. That is all this ladder does: it keeps your twelve bars and adds the chords, a few at a time, with the notes of your box that still fit and the ones to move.

Questions

What are the chords of a 12-bar blues?

Three dominant seventh chords, I7, IV7 and V7: four bars of I, two of IV, two of I, then V, IV, I and V. In A: A7, D7 and E7.

What is the difference between a blues and a jazz blues?

The same twelve bars and landmarks, with more chords in between: a ii–V into the IV in bar 4, a diminished chord in bar 6, VI7 in bar 8, a ii–V in bars 9–10 and a turnaround in 11–12.

What is a minor blues?

A 12-bar blues with minor I and IV chords and, in bars 9–10, ♭VI7 sliding to V7alt: The Thrill Is Gone in the blues, Mr. P.C. and Equinox in jazz.

What is a Bird blues?

Charlie Parker’s version of the 12-bar blues, the changes of Blues for Alice: a chain of ii–Vs falling by step from the I to the IV and back.

Does the minor pentatonic work over a jazz blues?

Over most of it, yes. It stops working on the new chords — the diminished, the VI7, the ii–Vs — and each step of this ladder shows which note to move, and where.