Dancing in the aisles
Saw it when I was 10 at the old Hilltop Theatre in Tujunga, CA. It was a double feature with Mysterious Island which is the movie I wanted to see. The theater was packed with teens and during the songs they left their seats and danced in the aisles. At least twice the movie was stopped and the manager got on stage and warned the teens to stop dancing.
Back in my day we had nine planets