Are you familiar with Songza?
the playlists on turntable were an organic composition of the community in the channel. the user was directly involved in the creation process. the playlist changed to reflect the people in the channel. it was an entirely social gathering (when it started anyway), as if you got 50 music heads into a room and asked them to rock out.
songza is purely curated. for that reason, it misses the social aspect. songza is more like hiring an extremely inexpensive dj. other users dont get to interact with the playlist content.
different approaches to the same problem, but i believe the real innovation is in combining humans minds and experiences in searching the song graph. songza does not do that. turntable did.
songza still cool tho!