Chord sequence
G♭maj7 Gdim7 A♭m7 G7
In every key
Four-note rootless voicings in their two forms, with the 3rd or the 7th on the bottom, played over the root.
Heard in Gb major
Over Gbmaj7 · Imaj7
The major scale and its modes are the most commonly used scales in western music.
Over Gdim7 · ♯i°7
Mode 7 of Harmonic Minor
Over Abm7 · ii7
Mode 2 of Major
Over G7 · subV7
Mode 4 of Melodic Minor