Why do I have to sign up or sign in to Yahoo! Music?
[p/[Yahoo! Music provides customized music recommendations, your own customized radio and video stations, and much more. You tell us your preferences by ratings music and video on the site, in video and radio players, or in the Yahoo! Music Jukebox, However, your ratings and custom music profile are tied to your Yahoo! ID. If you don't sign up for a Y! ID, we can't associate your music preferences with anything. If you have a Y! ID but don't sign in, we can't tell who you are, so your music recommendations and customized stations won't come up.
Signing up and signing in are free, as are your music recommendations services, radio and video stations, etc.