Rock music, yes. Worst sort, no. They were a cut above the rest in their day.

It's a matter of opinion, of course, but I disagree. They began as a bad Zep knockoff and then things got worse. I was around in 'their day', seen them more than once (before they were headliners) and never liked 'em. Technically proficient as all get out (credit where it's due), but (to me) boring and more pretentious/up-its-own-arse than most of its ilk.