Chords in E Locrian

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

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