Nursery rhymes and catchy tunes are a good way of learning a language, I absolutely agree with you. It doesn't really matter whether the songs are cheesy or not, all that matters is learning - if you can learn something from them, then so be it. When it comes to Andrea Boccelli, I really love his version of Time to Say Goodbye (with Sarah Brightman - her voice is simply magical and fairy tale-like). If nothing, you can pick up some words and phrases in Italian while listening to it. I've also mentioned Emma Chapplin. She's French, true, but she also sings in Italian. It's quite popular nowadays, actually, just like it had been in the past, as after all, Italian is the language of opera.