The best music curation I experienced was a service called Songza, which was acquired by and absorbed into google music. I still have a subscription to google play music, even though the songza playlists had gotten hard enough to find at one point that I stopped trying.

This article & discussion was enough for me to stop working briefly and go research whatever happened, and apparently Peter Asbill is still at Google and I should try again.

Update: holy shit, yeah.