Chord sequence
Amaj7 F♯m7 Bm7 B♭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 A major
Over Amaj7 · Imaj7
The major scale and its modes are the most commonly used scales in western music.
Over F#m7 · vi7
Mode 6 of Major
Over Bm7 · ii7
Mode 2 of Major
Over Bb7 · subV7
Mode 4 of Melodic Minor