What's the difference (in fashion) between a Guido and a Rock Star?

I'm confused. Aren't they two different styles? Because unless I detect a blowout, they look and dress the same to me. Both styles wear graphic t-shirts featuring skulls, crosses, angel wings, etc... both styles wear wrist cuffs, designer jeans, and swag chains. How am I supposed to identify a Guido from a Rock Star?