Chord sequence
D7 G7 D7 G7 D7 A7 G7 D7 E♭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 D major
Over D7 · V7/IV
Mode 5 of Major
Over G7 · IV7
Mode 4 of Melodic Minor
Over D7 · I7
Over A7 · V7
Over Eb7 · subV7