Always on the look out for all things co-op. Co-op taxi firms, cinemas, cafes...yeah, yeah, yeah. But didn't expect to find anything on iTunes. Just waiting for a download and ran a search. How about Co-operative Music.
Might be based in Sweden but covers artists through Europe, Brazil, USA, Australia. A collective of independent labels. Plenty there. I'll get back after dipping in for a sample. It's the age of democratic publishing but you still need someone to separate the signal from the noise and find the gems.