title: Select music file in windows phone 8
body: <p>I want to create an app which will let the user open an mp3 file.
  I am using FileOpenPicker but get the error while creating an object of FileOpenPicker itself.</p>
  
  <pre><code>FileOpenPicker filePicker = new FileOpenPicker();
  </code></pre>
  
  <p>This line is throwing an error:
  An exception of type 'System.NotSupportedException' occurred in PhoneApp1.DLL but was not handled in user code.</p>
  
  <p>Can someone tell me what is the problem here.</p>