Chord sequence

Cm7, B7, Bbm7, A7

Cm7 B7 B♭m7 A7

Tempo 120 BPM

Rootless Shells Guide tones Rooted shells Rooted Drop 2

Four-note rootless voicings in their two forms, with the 3rd or the 7th on the bottom, played over the root.

Customize each chord

Cm7
B7
Bbm7
A7

Analysis

Heard in G# major

Each chord's roman numeral and role in G# major
Chord	Numeral	Role
Cm7	♭iv7	Diatonic
B7	subV7/ii	Tritone substitute for V7/ii
B♭m7	ii7	Subdominant
A7	?	Outside the key (bII7)

Progressions in these changes

All the chords

Chromatic iii-bIII-ii-bII Progression in Ab

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

Scales to play