Your progression consists of two chords: Gm7 and Dm7. Seeing as though these chords are both in the key of B flat major, and they each have an D in them (D is the dominant/5th in the Gm7 and the tonic/root note in the Dm7), you can use the D phrygian mode to solo over both of them. Also, if you're so inclined (which I am), you could use A locrian
(
Read more... )