Chords in D Lydian

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

Beyond those seven, D Lydian commonly borrows Dm (i), Edim (iiø), F (bIII), Gm (iv) and Am (v) from the parallel minor — the mixture chords that give a progression somewhere unexpected to go.