A Web site that recommends new songs based on one or more favorite songs selected by the user. The service may also be available on iPhones, BlackBerrys and other smartphones and may use a proprietary technology for song selection, collaborative filtering or both. Collaborative filtering is based on the likes and dislikes of millions of users. For example, Pandora and Last.fm are two leading recommendation sites that stream the music to the user. See Pandora, Last.fm and music search.