Chord sequence
D♭7 G♭7 C♭7 G7 Amaj7
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 Db7 · V7
Mode 5 of Major
Over Gb7 · V7/IV
Over Cb7 · IV7
Mode 4 of Melodic Minor
Over G7 · ?
Mode 6 of Blues
Over Amaj7 · ♭IIImaj7
Mode 4 of Major