the apps are suspended when you switch away from them
The app must support background tasks to continue to play:
http://blogs.msdn.com/b/windowsappdev/archive/2012/05/16/being-productive-when-your-app-is-offscreen.aspx
http://blogs.msdn.com/b/windowsappdev/archive/2012/05/24/being-productive-in-the-background-background-tasks.aspx
"A programmer is just a tool which converts caffeine into code"
