Chords in C Locrian

C Locrian is built from the notes C, Db, Eb, F, Gb, Ab and Bb. Its scale carries 5 flats. Harmonising that scale in thirds gives seven chords — 3 majors, 3 minors and 1 diminished — starting on Cdim as the iø. The chord on the fifth degree is Gb, a major bV, so C Locrian has the leading tone that makes a Gb-to-Cdim cadence sound final.

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