rock and roll which first emerged in the 1950's is a union of which two styles
Rock and roll Rock and roll (often written as rock & roll or rock 'n' roll) is a genre of popular music that originated and evolved in the United States during the late 1940s and early 1950s,[1][2] from African American musical styles such as gospel, jump blues, jazz, boogie woogie, and rhythm and blues,[3] along with country music.[4] While elements of rock and roll can be heard in blues records from the 1920s[5] and in country records of the 1930s,[4] the genre did not acquire its name until 1954.[6][7]