I could be wrong but wasn't Rock and Roll like a term for being "different" sort of, I was at the RNRHOF last January, and I thought that's what it said in a write up on Alan Freed, the famous Radio DJ. I checked his Wikipedia(I know...I know) and when he described Rock and Roll I got this.... "Rock and Roll" is a river of music that has absorbed many streams: rhythm and blues, jazz, rag time, cowboy songs, country songs, folk songs. All have contributed to the big beat"