Magnatunes

I think of Magnatune as the standard bearer for open music.

They:
[1] Always share half of their proceeds with the artists they distribute.
[2] Provide you with multiple download options, including OGG, FLAC, and even uncompressed digital audio (as well as a variety of MP3 options).
[3] License music freely to nonprofit and open projects (including a generous, free podcast license; the notion of 'nonprofit' is not limited to the strict legal definition).
[4] They're not evil.

I've purchased a number of recordings from them in the past, and think it is a marvelous experiment in open licensing and distribution of high quality music from independent artists.

I'm in no way affiliated; I'm just a happy customer.