A big band is a type of large ensemble jazz group that typically consists of 12 to 20 musicians. The instrumentation of a big band typically includes saxophones, trumpets, trombones, a rhythm section (piano, bass, drums, and guitar), and sometimes other instruments such as clarinets, flutes, and vocalists. Big bands are typically led by a conductor or bandleader, who is responsible for arranging the music and leading the band's performance.