MPMediaPickerController *picker = [[MPMediaPickerController alloc] initWithMediaTypes:MPMediaTypeAnyAudio];
picker.prompt = @"请选择需要播放的歌曲";
picker.showsCloudItems = NO;
picker.allowsPickingMultipleItems = YES;
picker.delegate = self;
[self presentViewController:picker animated:YES completion:nil];


- (void)mediaPickerDidCancel:(MPMediaPickerController *)mediaPicker
{
    [mediaPicker dismissViewControllerAnimated:YES completion:nil];
}

- (void)mediaPicker:(MPMediaPickerController *)mediaPicker didPickMediaItems:(MPMediaItemCollection *)mediaItemCollection
{
    [mediaPicker dismissViewControllerAnimated:YES completion:nil];
    //do something
}

// Base queries which can be used directly or as the basis for custom queries.
// The groupingType for these queries is preset to the appropriate type for the query.
+ (MPMediaQuery *)albumsQuery;
+ (MPMediaQuery *)artistsQuery;
+ (MPMediaQuery *)songsQuery;
+ (MPMediaQuery *)playlistsQuery;
+ (MPMediaQuery *)podcastsQuery;
+ (MPMediaQuery *)audiobooksQuery;
+ (MPMediaQuery *)compilationsQuery;
+ (MPMediaQuery *)composersQuery;
+ (MPMediaQuery *)genresQuery;

MPMediaPropertyPredicate *artistNamePredicate =
[MPMediaPropertyPredicate predicateWithValue:@"Happy the Clown"
                                 forProperty:MPMediaItemPropertyArtist
                              comparisonType:MPMediaPredicateComparisonEqualTo];

MPMediaQuery *quert = [[MPMediaQuery alloc] init];
[quert addFilterPredicate: artistNamePredicate];
quert.groupingType = MPMediaGroupingArtist;

NSArray *itemsFromArtistQuery = [quert items];
NSArray *collectionsFromArtistQuery = [quert collections];

// Returns the value for the given entity property.
// MPMediaItem and MPMediaPlaylist have their own properties
- (id)valueForProperty:(NSString *)property;

// Executes a provided block with the fetched values for the given item properties, or nil if no value is available for a property.
// In some cases, enumerating the values for multiple properties can be more efficient than fetching each individual property with -valueForProperty:.
- (void)enumerateValuesForProperties:(NSSet *)properties usingBlock:(void (^)(NSString *property, id value, BOOL *stop))block NS_AVAILABLE_IOS(4_0);

// Playing media items with the applicationMusicPlayer will restore the user's iPod state after the application quits.
+ (MPMusicPlayerController *)applicationMusicPlayer;

// Playing media items with the iPodMusicPlayer will replace the user's current iPod state.
+ (MPMusicPlayerController *)iPodMusicPlayer;

The iPod music player employs the iPod app on your behalf. On instantiation, it takes on the current iPod app state and controls that state as your app runs. Specifically, the shared state includes the following:
Repeat mode (see “Repeat Modes”)
Shuffle mode (see “Shuffle Modes”
Now-playing item (see nowPlayingItem)
Playback state (see playbackState)

Other aspects of iPod state, such as the on-the-go playlist, are not shared. Music that is playing continues to play when your app moves to the background.

The application music player plays music locally within your app. It does not affect the iPod state.
When your app moves to the background, the music player stops if it was playing.

// Call -play to begin playback after setting an item queue source. Setting a query will implicitly use MPMediaGroupingTitle.
- (void)setQueueWithQuery:(MPMediaQuery *)query;
- (void)setQueueWithItemCollection:(MPMediaItemCollection *)itemCollection;

// Returns the currently playing media item, or nil if none is playing.
// Setting the nowPlayingItem to an item in the current queue will begin playback at that item.
@property(nonatomic, copy) MPMediaItem *nowPlayingItem;

//AVAudioPlayer
- (id)initWithContentsOfURL:(NSURL *)url error:(NSError **)outError;

//AVPlayer
+ (id)playerWithURL:(NSURL *)URL;
- (id)initWithURL:(NSURL *)URL;

//A URL pointing to the media item,
//from which an AVAsset object (or other URL-based AV Foundation object) can be created, with any options as desired. 
//Value is an NSURL object.
MP_EXTERN NSString *const MPMediaItemPropertyAssetURL;

@interface MyClass : NSObject
{
  AVAudioPlayer *_player;
  //AVPlayer *_player;
}

//设置AudioSession
[[AVAudioSession sharedInstance] setActive:YES error:nil];
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];

//play
NSError *error = nil;
MPMediaItem *item = ...;
NSURL *url = [item valueForProperty:MPMediaItemPropertyAssetURL];
_player = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error];
//_player = [AVPlayer playerWithURL:url];
[_player play];