One of the mysteries of the English language finally explained.
A person who performs, dances to, or enjoys rock 'n' roll music; (also occasionally) a rock 'n' roll song or record. In later use also more generally: a rock musician; a rock song.
1950s. From rock 'n' roll + -er. Compare slightly earlier rocker and slightly later rocker.
rock 'n' roller/ˌrɒk (ə)n ˈrəʊlə/
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