iTunes won't play any music?

[GizmoDVD]

So I updated to the newest version of iTunes today and upgraded my iPhone to 1.1.1.

Now, any music in my iTunes library will not play. The top of the screen shows the song title and artists name/album, and the run time...but nothing happens. I hit play...nothing. I try clicking randomly along the track...nothing. My volume is up (I can load up Youtube with no issues). Anyone know why?

[GSA190]

I had the same problem. Just restart your whole computer. Everything worked fine after I restarted it.