Chord sequence
F♯7 B7 F♯7 B7 F♯7 C♯7 B7 F♯7 G7
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
Over F#7 · V7/IV
Mode 5 of Major
Over B7 · IV7
Mode 4 of Melodic Minor
Over F#7 · I7
Over C#7 · V7
Over G7 · subV7