♪ every time i think about it i want to cry ♪ >> the '70s the groups started to become more theatrical. they realized just giving them the music isn't enough. we got to give them something to look at. >> more naked people, more misbehavior, more over the top stuff going on. just -- just more. ♪ oh ♪ ♪ no time ♪ >> playing stadiums was too unreal. it would just be a sea of faces into infinity. ♪ with your sweet bag of lies ♪ ♪ crazy, crazy, crazy ♪ ♪ crazy on you ♪ >> stadium tours put a lot of people near music. what they also do is force the musicians to play to the back of the hall.