premise: Creedence Clearwater Revival was a rock band.
hypothesis: Creedence Clearwater Revival , often informally abbreviated to Creedence or CCR , was an American rock band active in the late 1960s and early 1970s . Despite their San Francisco Bay Area origins , they played in a Southern rock style , with lyrics about bayous , catfish , the Mississippi River , and other popular elements of Southern United States iconography , as well as political and socially-conscious lyrics about topics including the Vietnam War .