Playlists having media items from more than one source are described. Media items in a first library are mapped to media items from an online media item store. Media items within the playlist that can be found in the first library will be played from the first library, while media items not within the first library will be played from the online media store. By identifying media items present in both libraries and playing them only from the first library, the described method can reduce the royalties needing to be paid by the online media store. Further methods are disclosed for setting limits on the number of media items that can be shared by a second library.