ios iphone audio mpmusicplayercontroller

MPMusicPlayerController won't interact with Remote Controls

even though this question ist asked many times and I didn't find any satisfying answer to this, I still wanna give it another try:

I'm trying to play MPMediaItems with the MPMusicPlayerController. So far so good. This is needed to play files from Itunes Match or Apple Music. Any other files are played via AVPlayer.

Handling remote controls for songs played with the AVPlayer seems to be no problem using:

[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
[self becomeFirstResponder];

and

- (void)remoteControlReceivedWithEvent:(UIEvent *)receivedEvent

Also it is possible to retrieve AVPlayerItemDidPlayToEndTimeNotification in background reacting on this to start playing next song.

Trying all of this playing a song with MPMusicPlayerController doesn't seem to work as it should. I'm trying to play a song like this:

 self.audioPlayer = [MPMusicPlayerController applicationMusicPlayer];
 self.audioPlayer.repeatMode = MPMusicRepeatModeNone;
 [self.audioPlayer setQueueWithItemCollection:[MPMediaItemCollection collectionWithItems:@[_playerItem]]];

using the given observers:

[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(playbackStateDidChange:) name:MPMusicPlayerControllerPlaybackStateDidChangeNotification object:nil];
[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(playbackItemDidChange:) name:MPMusicPlayerControllerNowPlayingItemDidChangeNotification object:nil];
[self.audioPlayer beginGeneratingPlaybackNotifications];

If the app is in foreground the observers are called as they should. Going into background the observers are not called anymore. In this case it is not possible for me to detect the end of a song to skip to the next song.

Also - remote controls wont work. I used:

[MPRemoteCommandCenter sharedCommandCenter].playCommand.enabled = YES;
[[MPRemoteCommandCenter sharedCommandCenter].playCommand addTarget:self action:@selector(remotePlay)];

[MPRemoteCommandCenter sharedCommandCenter].pauseCommand.enabled = YES;
[[MPRemoteCommandCenter sharedCommandCenter].pauseCommand addTarget:self action:@selector(remoteStop)];

[MPRemoteCommandCenter sharedCommandCenter].previousTrackCommand.enabled = YES;
[[MPRemoteCommandCenter sharedCommandCenter].previousTrackCommand addTarget:self action:@selector(loadPreviousSong)];

[MPRemoteCommandCenter sharedCommandCenter].nextTrackCommand.enabled = YES;
[[MPRemoteCommandCenter sharedCommandCenter].nextTrackCommand addTarget:self action:@selector(loadNextSong)];

But nether in foreground nor in background these given selectors are called.

Does anyone have a solution to my problem? As said I need to use MPMusicPlayerController as I want to playback Apple Music and iTunes Match tracks.