Rock and Roll: Musical genre of marked rhythm, derived from a mixture of various genres of American folk music, (Doo Wop, rhythm and blues, hillbilly, blues, country and western are the most prominent) and popularized since the 1950s, being his most influential singer Elvis Presley, his most influential guitarist Chuck Berry and his most influential bands, Eddie Cochran, and Bill Haley and The Comets among others.
It was the Plains Indians who built large cities, and traded far and wide, although it should be noted that here, "large" is a relative term. These were not cities on the scale of most East Coast cities.
