[techtalsky]

It seems like there's a possibility you could work with one of these artists in some kind of promotion deal. You could have limited distribution of their track as a test app, and they could get a little promotion along with your cool space-age idea. I bet a nice email to their PR people would be worth it.

[nitrogen]

I am not from Germany, but I seem to remember reading that the GEMA licensing is mandatory even for bands that give their music away for free. Can anyone clarify if that's the case?