In the first Back to the Future, Michael J. Fox has entered the talent contest at his parents high school. He is doing Chuck's famous duck walk and playing one of his famous hits.
Backstage, one of the musicians is on the phone: Chuck, this is your cousin Marvin, Marvin Berry. Listen, I think I just found that sound you've been looking for!

Just my opinion but here it is:
Chuck Berry, Lil Richard, Fats Domino and Elvis the Pelvis - the heart of early Rock 'n Roll.
I started listening to R 'n R on the radio around 1958 or so. I remember feeling good about liking this music. These guys were defining the music.
Gene