Chords in Ab Phrygian

Ab Phrygian is built from the notes Ab, Bbb, Cb, Db, Eb, Fb and Gb. Its scale carries 8 flats. Harmonising that scale in thirds gives seven chords — 3 majors, 3 minors and 1 diminished — starting on Abm as the i. The chord on the fifth degree is Ebdim rather than a major VØ, so Ab Phrygian has no leading tone and resolves by step and colour instead of by dominant pull — the sound that separates it from a plain Ab major.

Beyond those seven, Ab Phrygian commonly borrows Ab (I), Bbm (ii), Cm (iii), Db (IV) and Eb (V) from the parallel major — the mixture chords that give a progression somewhere unexpected to go.