Chord sequence

Gb7, Cb7, Gb7, Cb7, Gb7, Abm7, Db7, Gb7, Db7

G♭7 C♭7 G♭7 C♭7 G♭7 A♭m7 D♭7 G♭7 D♭7

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

Gb7
Cb7
Gb7
Cb7
Gb7
Abm7
Db7
Gb7
Db7

Analysis

Heard in Gb major

Each chord's roman numeral and role in Gb major
Chord	Numeral	Role
G♭7	V7/IV	Secondary dominant of IV
C♭7	IV7	Blues dominant
G♭7	V7/IV	Secondary dominant of IV
C♭7	IV7	Blues dominant
G♭7	I7	Blues dominant
A♭m7	ii7	Subdominant
D♭7	V7	Dominant
G♭7	I7	Blues dominant
D♭7	V7	Dominant

Progressions in these changes

All the chords

Blues with ii-V in Gb

The basic blues with a ii-V in bars 9 and 10 in place of V-IV, and a V7 turnaround in the last bar.
Chords 6 to 7

Major ii-V Progression in Gb

Abm7 Db7

Scales to play