Chord sequence
D♭maj7 B♭7 G♭m7 B7
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 3 to 4
Gbm7 B7
Over Dbmaj7 · Imaj7
The major scale and its modes are the most commonly used scales in western music.
Over Bb7 · V7/ii
Mode 6 of Blues
Over Gbm7 · iv7
Mode 2 of Major
Over B7 · ♭VII7
Mode 4 of Melodic Minor