Genre characterized by an instrumentation consisting of three sections of horns (trumpet, trombones, and saxes) and a rhythm section consisting of piano, bass, drums, with optional guitar and vibes. Most big bands play swing and jazz but many play virtually any musical style. Many are named for their leaders. Careful arranging is needed to avoid anarchy, but jazz big band arrangements allow plenty of room for improvisation. Characteristic writing utilizes call-and-response phrasing by the horn sections as well as harmonized tutti ensembles.

The Big Band Era is generally considered to date from the mid-1930s to the end of World War II, the heyday of such leaders as Glenn Miller, Tommy and Jimmy Dorsey, Count Basie and Chick Webb. The postwar decline of "name" bands is blamed on the rise of singers as solo artists, but renewed interest in the genre can be credited to authentic re-creations and new arrangements recorded by modern vocalists such as Linda Ronstadt and Harry Connick, Jr.

Many communities boast big bands which meet to rehearse and to play for dances attended by seniors, made possible in part because musicians will play for little or no money just to be part of a big band. On the other hand, bands consisting of the best local and regional musicians command top dollar when enlisted to play for society benefits and parties, or to accompany touring singers whose arrangements typically call for groups of sixteen pieces or even more.

The style is an oddity, then, attracting hobby performers like a folk art but requiring carefully prepared arrangements like a fine art. University music departments are an important center of training for big band performers, not only as a source of arrangements but also as a place to learn how to phrase correctly so as to blend with a section.