One of rock and roll's great achievements is helping to bridge the racial divide. Rock made it acceptable for white people to listen music created by African-Americans (or why the term "race record" is now outmoded) and for blacks and whites to socialize to hear music together. Which is why I kept shuddering watching the profile of Lyrnyrd Skynyrd on the Rock and Roll Hall of Fame induction ceremony. The Confederate flag was a ubiquitous presence at their performances; they might as well have hung a huge sign, "Black people not welcome."
I was never a fan of Black Sabbath, but at this point I must
acknowledge that they have been hugely influential on an entire genre
of music. The Sex Pistols recorded only one studio album, but its
impact was utterly cataclysmic. I'm not convinced that Miles Davis is
rock and roll, but he was one of the greatest innovators in music.
Blondie has it all going in spades. But Lynard Skynyrd is a
two-hit-wonder that did little to advance rock and roll, and they had a
habit of endorsing racial segregation.