How to stop music W8 Xbox music app

First looks at W8 and having difficulty with user interface (non touch computer)

I started the music app and cannot see how to stop the app it self, play music consantly, has forward pause and reverse buttons but I cannot find a way to stop the music (looks like play all is on).

Any help direction much appreciated.

I know I can Pause the music but how to I stop a song (or is it just the pause) and exit???