Throughout the '50s, tons of unknown locals came through Sun to record their demos. Elvis Presley, Johnny Cash, and Jerry Lee Lewis all made their first recordings at the former Memphis Recording Service.
Somewhere along the line, a concert became a variety show. It was no longer enough for four dudes to play together in front of some guitar amps. Costume changes, an army of dancers, and Broadway theatrics suddenly became standard for a 'concert.'
Blues became rock, rock became soul, and all of it was colorblind.