I wanna rock. I was born to rock. Rock is a murky term at best, and it encompasses so much more than just music. On that level, grunge rocked. A good deal of rap and about half of jazz rocks.
Pop can rock, if it's smart.
Surprisingly, rock usually doesn't rock. Disco is still the anti-rock. Metal never, ever rocked, except Ozzy. Lilith Fair, try as hard as it might, won't rock until it actually gets out there and, well, rocks. But Chrissie Hynde rocks.