The Beatles at Shea Stadium (1965)
The Beatles' concert at Shea Stadium in New York City in 1965 marked the first time that a rock band used a sports stadium as a concert venue. This event had 55,000 attendees, 2000 security personnel, and a record-breaking $304,600 gross; but the most important number was 100 — that is, the custom 100-watt amplifiers that Vox made for the Moptops' tour.
Overwhelmed by the huge stadium and the frantic screaming fans, the amps couldn't cut it: Even with the support of the in-house PA system, concertgoers simply couldn't hear the band. What's more, the Fab Four couldn't hear themselves, either, which led to shenanigans like John Lennon playing the keyboard with his elbows
. From here on, live rock shows got even bigger — and so did the speakers.