Chord sequence
D♯m7 G♯7 C♯m7 F♯7 Bm7 E7 F♯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 F# major
All the chords
Three ii-Vs, each a whole step below the last and the last one the backdoor ii-V: a chain of keys that doesn't arrive until the end.
Over D#m7 · vi7
Mode 6 of Major
Over G#7 · V7/v
Mode 5 of Melodic Minor
Over C#m7 · ii7/iv
Mode 2 of Major
Over F#7 · V7/iv
Over Bm7 · iv7
Over E7 · ♭VII7
Mode 4 of Melodic Minor
Over F#maj7 · Imaj7
The major scale and its modes are the most commonly used scales in western music.