Sorry for not being clear enough. It's not that torrents as protocol are illegal. So yes, it is totally legal to distribute any content you have rights to distribute, such as Linux distros, creative commons material, you name it.

It would also be legal for you to share a music file to, for instance, your friend who lost it's original copy but already paid for the song. You simply can't redistribute the song on massive scale to people who didn't buy it, so that's torrenting weakness here. Also, the personal connections between you and the downloading party matters in determining if this was fair/"personal use".