title: How do I detect if other apps are playing background audio?
body: <p>I am making a game for iphone/ipad, and don't want my background music to interfere with music the user might already be playing.</p>
  
  <p>I know I can get the state of the iPod app using MPPlayerController, but how would my app figure out if something else, like Pandora, was playing background audio on iOS4?</p>