The term rock and roll is vague. It is sometimes used to describe a number of genres only distantly related, including soul, heavy metal and even hip hop. In other circumstances, it is used strictly to apply only to the earliest incarnation of "rock" -- the 1950s scene that started the genre. Some make distinctions between rock and roll and rock music on these grounds, while others unapologetically use it as a synonym for modern Western popular music
Birth of a counterculture (1968-1974)