Paco

Now kill the Dock to relaunch it:


Start playing a song in iTunes to see the notification appear, it'll disappear automatically and then reappear briefly anytime a new song starts.

If you decide you don't like the notification, disabling the iTunes song popup is just as easy:


You won't need to relaunch iTunes, but you will need to kill the Dock again.

This only works in Mac OS X 10.7 Lion, if you try it in prior versions nothing happens.

source: http://osxdaily.com/tag/mac-os-x-10-7/page/5/