IMHO, rock concerts are different than r n'b, pop, rap, or whatever the genres are.
the fans treat the concerts just like some cult ritual.
they MUST love rock music coz being in the rock concert really uncomfortable, and the fans pay more for festival ticket to feel the energy (i usually call it "the force"..hahahahah) than sitting in the tribune.
i mean...people with "common" sense would never pay more for festival ticket, it's not comfortable, it's hot, damp, and...jungle law rules! stronger men last till the end....
so....what you expect from people who treat rock music like some cult ritual is one great wave of energy in concert hall...they sing, they scream, they shout, they forget the world like there's no tomorrow, whoa....