Gm D7 Eb Bb Cm Gm Am7b5 D7
Gm D7 Eb Bb Cm Gm D7 Gm
It feels a little like a playing a minor version of Pachelbel's Greatest Hit.
Also tried alternating between Csus4 and Bbsus4 in a 3-3-3-2-2 rhythm, playing C minor or dorian for the melody. Hard to keep the rhythm going without making the improvisation kind of straightforward and dull, but that 6-and-half-beat pattern seems compelling somehow.