Backing track starts at1:30.
This backing track is a great way to practice improvising melodically over chord changes, four bars of Em followed by four bars of Gm in 7/4 time.. In the diagrams E Dorian mode is blue and G Dorian mode is orange, notes shared by both modes are half and half.
You will see some notes are not in
Also playlists of BT's by style https://www.youtube.com/channel/UCuzs8rKb4Dw8HbNAnHeLnhQ/playlists
Dorian Gm-Em Backing Track, And Target Note Practice Tips.