If it is difficult to define commercial speech, doesn't that chill speech?

Just the thought of a rap version of Beethoven's Fifth Symphony or 'Achy, Breaky Heart' is bound to make people smile.

We are looking for a federal issue here.

When Congress alters the federal balance, it must carefully consider the consequences of doing so.

It is rare that a regulation restricting speech because of its content will ever be permissible ... Indeed, were we to give the Government the benefit of the doubt when it attempted to restrict speech, we would risk leaving regulations in place that sought to shape our unique personalities or to silence dissenting ideas.

No, I can't do rap music!