Chord sequence
Dm7 G7 E♭m7 A♭7
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 Db major
Chords 1 to 2
Dm7 G7
Chords 3 to 4
Ebm7 Ab7
Over Dm7 · ♭ii7
Mode 6 of Blues
Over G7 · V7/vii
Over Ebm7 · ii7
Mode 2 of Major
Over Ab7 · V7
Mode 5 of Major