I wouldn't say JB was part on the like that invented rock. He was more of the soul music variety. The movie is bad because they kept going back to childhood and later dates over and over again.
I should phrase it differently, the pioneers of rock and roll in the 1960s, like the Beatles, Rolling Stones, etc., borrowed heavily from James Brown, Little Richard, and other African American musicians.
Mick Jagger's stage act is obviously influenced by Brown.
The origins of R and R came from R & B, blues and soul.
R & B is the blues. Elvis said rock and roll derived from blues, country and gospel. Chuck Berry said that he stoled from country and big band music (he named a couple, but can't recall at the moment). He said we all steal/borrow from one another.