Chords in C Mixolydian

C Mixolydian is built from the notes C, D, E, F, G, A and Bb. Its scale carries 1 flat. Harmonising that scale in thirds gives seven chords — 3 majors, 3 minors and 1 diminished — starting on C as the I. The chord on the fifth degree is Gm rather than a major V, so C Mixolydian has no leading tone and resolves by step and colour instead of by dominant pull — the sound that separates it from a plain C minor.

Beyond those seven, C Mixolydian commonly borrows Cm (i), Ddim (iiø), Eb (bIII), Fm (iv) and Ab (bVI) from the parallel minor — the mixture chords that give a progression somewhere unexpected to go.