Music recommendation is HARD. A lot of people don't think they like didgeridoo (which is where my expertise lies) until they hear a live performance of contemporary didge over a PA and they're in tears of joy (seriously, if you got the chance, give it a try - the stack of vibrations from this single, simple tube is amazing). IME, that wouldn't work for your average ear-buds or "smilie curve"-tuned over-ears. So, say, a friend convinces you to go to some concert with them - that would be a proper, healthy, sustainable music recommendation service. But of course that doesn't scale in any direction.

Best of luck with your project - I'll be checking back :-)