Chord sequence
A♭7 D♭7 G♭7 D7 Emaj7
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
Over Ab7 · V7
Mode 5 of Major
Over Db7 · V7/IV
Over Gb7 · IV7
Mode 4 of Melodic Minor
Over D7 · ?
Mode 6 of Blues
Over Emaj7 · ♭IIImaj7
Mode 4 of Major