I don't remember this being talked about. I'm also not sure of its history or affiliations, but I like it:
Pandora Self described as:
"...a music listening and discovery service. Pandora enables users to easily create streaming stations that explore their favorite parts of the music universe."
You customize a streaming station based on your current tastes. The station then plays songs you like AND recommends others you may like
based on preferences. You can then guide it throughout by discarding or complimenting song selection. And you can mark fav songs that you hear for future investigation.
I wish XM Radio had a station like this:
my 1st creation (lame title - I know - but that's an arbitrary name they used since I added RH first)