title: MPMediaQuery songsQuery always return nil
body: <p>Sample code is expected to play a song available from the iPhone library:</p>
  
  <pre><code>MPMusicPlayerController *myPlayer =
  [MPMusicPlayerController applicationMusicPlayer];
  [myPlayer setQueueWithQuery: [MPMediaQuery songsQuery]];
  [myPlayer play];
  </code></pre>
  
  <p>However an exception is thrown on SongsQuery as it returns nil.</p>