This Micro Lesson breaks down a Jazz Rhythm progression functioning in a "G" Modal harmony.
This progression takes on a very different approach in it's application of harmony since it does not stick to functioning within one key center.
Measures one and two operate independently of one another with the first measures "Gm7" chord being isolated in harmony from the second measures, "Bbm6."
Over each chord the jazz improvisor would need to play into the chord using either; Minor Pentatonic, Minor 7th arpeggio or the, "Dorian Mode," (based upon each chords root).
When the third measure appears, our movement from that previous "Bbm6" chord into the "Fm7" functions with some strength to push in a mild resolution toward the "F Minor."
The appearance of that, "Eb7 and Eb9," produce a functioning Aeolian mode anchor. The first step would be to learn the chord changes, then record them and study applying these scales over the changes.
It may take time, but with practice you should have success in creating melodies over these chords. Enjoy!
Micro Lesson 172: "G Minor /Modal" Jazz Progression