Major I-vi-ii-V Progression in Ab

Tritone substitutes

Abmaj7 Fm7 Bbm7 A7

Each dominant 7th that resolves down a fifth becomes the dominant a tritone away, which shares its 3rd and 7th, so the bass moves by half steps.

Backdoor dominants

Abmaj7 Fm7 Dbm7 Gb7

Each V7 resolving to a major chord comes in by the back door from bVII7, with iv7 for its ii, borrowed from the minor key.

Major I-VI-ii-V

Imaj7 VI7 | ii7 V7

In Ab: Abmaj7 F7 Bbm7 Eb7

The standard turnaround back to the top of a major tune, with VI7, the dominant of ii, in place of the diatonic vi chord.

Major iii-VI-ii-V

iii7 VI7 | ii7 V7

In Ab: Cm7 F7 Bbm7 Eb7

The I-VI-ii-V turnaround with iii, which shares three notes with the I chord, standing in for the tonic.

Diminished Passing Turnaround

Imaj7 ♯i°7 | ii7 V7

In Ab: Abmaj7 Adim7 Bbm7 Eb7

The I-VI-ii-V with a diminished 7th chord on #I in place of VI7, so the bass rises by half steps from I to ii.

Tritone Sub Turnaround

Imaj7 ♭III7 | ii7 ♭II7

In Ab: Abmaj7 B7 Bbm7 A7

The I-VI-ii-V with tritone substitutes for its dominants, bIII7 for VI7 and bII7 for V7, so the bass falls by half steps from bIII back to I.

Chromatic iii-bIII-ii-bII

iii7 ♭III7 | ii7 ♭II7

In Ab: Cm7 B7 Bbm7 A7

The iii-VI-ii-V turnaround with both dominants replaced by tritone substitutes, so the roots descend by half steps from iii to I.

Tadd Dameron Turnaround

Imaj7 ♭IIImaj7 | ♭VImaj7 ♭IImaj7

In Ab: Abmaj7 Bmaj7 Emaj7 Amaj7

A turnaround of major 7th chords on I, bIII, bVI and bII, named after the bebop composer and arranger Tadd Dameron.