African-American musicians in the 1940s and 1950s were developing rhythm and blues into a genre called rock and roll, which featured a strong backbeat and whose prominent exponents included Louis Jordan and Wynonie Harris. However, it was with white musicians such as Bill Haley and Elvis Presley, playing a guitar-based fusion of black rock and roll with country music called rockabilly, that rock and roll music became commercially successful. Rock music thereafter became more associated with white people, though some black performers such as Chuck Berry and Bo Diddley had commercial success.