Here is a famous exemple of a contract-like music distribution. Only available in the U.S, for $10 a month, you can access to all the music Rhapsody has. The down side, and what made the polemic, is that it is not DRM free, which means that you are limited in the use of the tracks you have downloaded. It is a model that needs to be developped and can be promising with the help of technology (c.f Rick Rubin).
Source: RHAPSODY
