FOSS gamedev and creative worlds

This is the kind of music that Minetest needs: http://www.youtube.com/watch?v=13pf8znXBFw

Na, needs to be a little more relaxed.

What about music played on a 'hang'?
I think that kind of music is quite relaxing and perfect for a game like minetest.
Good hang music can be found here (not creative commons) or here (Creative Commons; Album: On its way).
What do you think about that genre?