Traditionally, books on the history of rock music begin by defining rock music as the meeting of country music and rhythm’n'blues, which is roughly correct.

However, this definition is out of touch with today’s rock music. Today, rock music is a genre that employs sampling techniques, electronic instruments, digital/computer technology, cacophony, and ethnic sources (beyond African-American and Anglo-Irish).

It was Chuck Berry who invented rock and roll in 1955. Berry was a black man playing black music. But times had changed: white kids were listening to rhythm and blues throughout the Northeast, and white musicians were playing rhythm and blues side to side with country music. Rock and roll was inherited by white singers, such as Presley, who often performed songs composed by obscure black musicians. White rockers became gentler and gentler, thereby drowning rock and roll’s very reason to exist.

Source:

Scaruffi