Chords in F# Locrian

F# Locrian is built from the notes F#, G, A, B, C, D and E. Its scale carries 1 sharp. Harmonising that scale in thirds gives seven chords — 3 majors, 3 minors and 1 diminished — starting on F#dim as the iø. The chord on the fifth degree is C, a major bV, so F# Locrian has the leading tone that makes a C-to-F#dim cadence sound final.

Beyond those seven, F# Locrian commonly borrows F# (I), G#m (ii), A#m (iii), B (IV) and C# (V) from the parallel major — the mixture chords that give a progression somewhere unexpected to go.