13. A system for recommending music comprising: a genre classifier configured to: identify a granularity of a plurality of genres based on a request for music similarity; learn to differentiate between the plurality of genres based on the granularity; calculate a first profile according to the granularity, wherein the first profile comprises, for each of the plurality of genres, a likelihood that a music selection of a user is in the genre; and calculate a second profile according to the granularity, wherein the second profile comprises, for each of the plurality of genres, a likelihood that an unknown music selection is in the genre; and a similarity analyzer connected to the genre classifier configured to: obtain a first similarity score between the first profile and the second profile; and recommend the unknown music selection to the user based on the first similarity score.
18. The system of claim 13 , wherein the music selection of the user is stored on a music playing device and wherein the unknown music selection is stored by a music store.