Itunes playing songs slowly

My desktop Itunes just suddenly started playing songs slower today. It's only slightly - and it's more like it lags occasionally - it's not a consistent drag. I've just recently upgraded to the new Itunes version - I'm not entirely sure if that's the problem because I can't remember exactly when I did the upgrade and if I listened to the songs afterwards or if this is the first time. It also seems to have corresponded with a increase in static noise while playing.

But it's highly annoying and entirely ruining any listening experience for me. I tried to play the songs through Windows Media player and they did not have the same problem - so it's obviously an Itunes issues.