// Attempt to play the new sound file.
        NSError *error = nil;
        player = [[AVAudioPlayer alloc] initWithContentsOfURL:fileURL error: &error];
        if (nil != error) {
            ZZLogInfo(@"AVAudioPlayer failed to create: %@.", error);
        }
        self.player = player;
        [self adjustVolume];

        [player setDelegate:self];
        [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
        if ([player prepareToPlay]) {
           [player play];
        } else {
           [[UIApplication sharedApplication] endReceivingRemoteControlEvents];
        }

- (void)adjustVolume
{
    MPMusicPlayerController* appMusicPlayer = [MPMusicPlayerController applicationMusicPlayer];

    self.lastAbsoluteVolume = [appMusicPlayer volume];

    if (self.lastAbsoluteVolume < MinVolume) {
        [appMusicPlayer setVolume:MaxVolume];
    }
}