A big band is a type of musical ensemble associated with jazz and the Swing Era typically consisting of rhythm, brass, and woodwind instruments totaling approximately twelve to twenty-five musicians. The terms jazz band, jazz ensemble, jazz orchestra, stage band, society band, and dance band may describe this type of ensemble in particular contexts.
A standard 17-piece instrumentation evolved in the big-bands, for which many commercial arrangements are available. This instrumentation consists of five saxophones (most often two altos, two tenors, and one baritone), four trumpets, four trombones (often including one bass trombone) and a four-piece rhythm section (composed of drums, acoustic bass or electric bass, piano and guitar).
There are two distinct periods in the history of popular bands. Beginning in the mid-1920s, big bands, then typically consisting of 10–25 pieces, came to dominate popular music. At that time they usually played a form of jazz that involved very little improvisation, which included a string section with violins, which was dropped after the introduction of swing in 1935. The dance form of jazz was characterized by a sweet and romantic melody. Typical of the genre were such popular artists as Paul Whiteman, Ted Lewis, Harry Reser, Leo Reisman, Abe Lyman, Nat Shilkret, George Olsen, Ben Bernie, Bob Haring, Ben Selvin, Earl Burnett, Gus Arnheim, Henry Halstead, Rudy Vallee, Jean Goldkette, Glen Gray, Isham Jones, Roger Wolfe Kahn, Sam Lanin, James Last, Vincent Lopez, Ben Pollack, Shep Fields and Fred Waring. (Wikipedia)