A big band is a type of musical ensemble that usually consists of ten or more musicians with four sections: saxophones, trumpets, trombones, and a rhythm section. Big bands originated during the early 1910s and dominated jazz in the early 1940s when swing was most popular. The term big band is also used to describe a genre of music. One problem with this usage is that it overlooks the variety of music played by these bands. Big bands started as accompaniment for dancing. In contrast with the e