Chord sequence
Cm7 E♯7 C♯m7 F♯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 B major
Chords 1 to 2
Cm7 E#7
Chords 3 to 4
C#m7 F#7
Over Cm7 · ♭ii7
Mode 6 of Blues
Over E#7 · V7/vii
Over C#m7 · ii7
Mode 2 of Major
Over F#7 · V7
Mode 5 of Major