We'll be in Athens at the beginning of May.
Any shows/performances of greek dances/music you recommend?
I've read very good reviews about this theater style show:
https://www.grdance.org/en/greek-dances-theatre-dora-stratou/
Unfortunately I'm seeing that it doesn't begin until 29th May and runs until 21 September. Much too early for my visit and for yours as well. But perhaps someone will benefit.
The Psyri neighborhood has a few cafes and restaurants with musicians. Just walk the pedestrian streets and listen. You'll find them.
https://maps.app.goo.gl/hhCwTakhhbJ5wX6i8
I also suggest (more fun, in my opinion) the Athens Street Food Festival in Gazi neighborhood - Metro station: Kerameikos), which takes place the first three weekends of May. Music, Food, Party: all in one place :))