Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online.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, primarily from a combination of the blues, country music and gospel music. Though elements of rock and roll can be heard in country records of the 1930s, and in blues records from the 1920s, rock and roll did not acquire its name until the 1950s. An early form of rock and roll was rockabilly, which combined country and jazz with influences from traditional Appalachian folk music and gospel.