To access the MediaLibrary Class, you should add the reference of the Microsoft.xna.Framework dll to your Windows Phone Application and add the following Namespace Microsoft.Xna.Framework.Media;

Add the following code snippet

private void ListSongs()
       {        
           MediaLibrary lib = new MediaLibrary();
           var SongName = (from m in lib.Songs
                      select m.Name).ToList();
           listBox1.ItemsSource = SongName;         
       }

The MediaLibrary Class includes the Songs property which is a SongsCollection . In the Above example the LINQ Query is used to retreive the Names of the songs from the Songs Collection .

You should see the list of songs as shown below .

Did you notice the list of songs in Emulator?

• Another Melody Song
• Melody Song
• Rhythm Variation

These are the default songs that are included in the Emulator

The MediaLibrary class also includes the Genre property to find Songs by Genre

MediaLibrary lib = new MediaLibrary();
 var Genre = (from m in lib.Genres
                       select m.Name).ToList();
  listBox1.ItemsSource = Genre;

You can also display the Albums using the property Albums defined in the MediaLibrary class

MediaLibrary lib = new MediaLibrary();
var Albums = (from m in lib.Albums
                       select m.Name).ToList();
listBox1.ItemsSource = Albums;

Source: http://windowsphonerocks.com/Developer/DeveloperArticles/tabid/64/Article/185/how-to-get-the-list-of-songsgenresalbums-from-the-windows-phone-medialibrary.aspx