Use an MPMusicPlayerController object, or music player, to play media items from the device iPod library.
Use an mpmusicplayercontroller object, or music player, to play media items from the device iPod library. There are two types of music player:
The application music player plays music locally within your app. It is not aware of the iPod app’s now-playing item, nor does it affect the iPod state.
The iPod music player employs the built-in iPod app on your behalf. On instantiation, it takes on the current iPod app state, such as the identification of the now-playing item. If a user switches away from your app while music is playing, that music continues to play. The iPod app then has your music player’s most recently-set repeat mode, shuffle mode, playback state, and now-playing item.