catch notification from iPod player.

gistfile1.txt

// (link MediaPlayer.framework)

// get item changed notification
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(changePlayerStatus:) name:MPMusicPlayerControllerNowPlayingItemDidChangeNotification object:nil];
	
// get status changed notification
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(changePlayerStatus:) name:MPMusicPlayerControllerPlaybackStateDidChangeNotification object:nil];
	
// get volume changed notification
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(changePlayerStatus:) name:MPMusicPlayerControllerVolumeDidChangeNotification object:nil];

[[MPMusicPlayerController iPodMusicPlayer] beginGeneratingPlaybackNotifications];