Chuck Berry and fellow rocker Jerry Lee Lewis once got into a fight over who was the true king of rock and roll. Each one was, of course, advocating for himself. Chuck "whupped butt," in Lewis' words. (Source)
In need of some affirmation, Jerry Lee Lewis brought the dispute to his mother. She let him in on the secret: Chuck, not Jerry, took the cake. Johnny B. Goode is the archetype, and Chuck is the real thing. "He's the king of rock n' roll," said Jerry Lee. "My mama told me that." That's a pretty serious calling card.