[ubuntu] I hate rhythmbox-how do I kill it?

I know I can remove rhythmbox and I will, but first I want to get an answer to this question.

When I launch rhythmbox and play a song I can click the "X" at the top of the window and rhythmbox disappears from my screen. However, the song keeps playing. I can not stop the song unless I first go to the dashboard, find rhythmbox, open it and then close it at the file menu. Is there an easier way to kill the song?