I didn't know that, having grown up with them on the radio but never having found it "my style": too rough, harmonies too shaky, etc.
But live, in a small theatre, this is just fun. I've watched it many times and hope to watch it many more.
It's hard to find good concert movies (I find), but this is one.
(They're still rough. Their harmonies are still abysmal. But i) it sounds great overall and ii) it's fun to watch them having fun!