as Fabio pointed out, everyone in Italy studies a bit of English at school, therefore we make little effort to improve our English skills by listening songs sung in English. So if you want to try learn italian by listening to Italian songs, that would be better if you already know some basics of the language.
I also agree with Andrew, that listening to songs in a foreign language helps a lot to fix in one's mind words and sentences, due to the pleasure you get when you listen to them together with a nice tune.
When I was at the very begininning of English studies, I used to translate by myself the songs I really liked, I used to do plenty of translations, and I also got myself books with translations of songs Ii liked. This helped me a lot to love the English language and be motivated to improve it, so that I would have been able, in the future, to understand a nice song at the first (or maybe second) listening ^_^