Chord sequence
E♭m7 A♭7 D♭maj7
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
All the chords
The most common cadence in jazz: a ii-V resolving to the major 7th tonic.
Over Ebm7 · ii7
Mode 2 of Major
Over Ab7 · V7
Mode 5 of Major
Over Dbmaj7 · Imaj7
The major scale and its modes are the most commonly used scales in western music.