Rock and roll is a genre of popular music that evolved in the United States in the late 1940s and early 1950s. Its 1 lie mainly in blues, rhythm and blues, country, folk, gospel, and jazz. The style subsequently spread to the rest of the world and developed further, leading ultimately to 2 rock music. The term “ rock and roll ” now covers at least two different meanings, both in common usage. The American Heritage Dictionary and the Merriam-Webster Dictionary both 3 rock and roll as synonymous with rock music. 4 , Allwords.com defines the term as referring specifically to the music of the 1950s. Classic rock and roll is 5 played with one or two electric guitars, a string bass or an electric bass guitar, and a drum kit. In the 6 rock and roll styles of the late 1940s, either the piano or saxophone was often the lead instrument, but these were generally 7 or supplemented by the guitar in the middle to late 1950s. The massive popularity and eventual worldwide view of rock and roll gave it a 8 social impact. Far beyond simply a musical style, rock and roll, as seen in movies and in the new medium of television, 9 l ifestyles, fashion, attitudes, and language. It went on to spawn various sub-genres, often without the initially 10 backbeat, that are now more commonly called simply “ rock music ” or “ rock ” . A) define I) followed B) characteristic J) modern C) unique K) explanation D) roots L) Conversely E) usually M) replaced F) Basically N) prepare G) earliest O) seldom H) influenced