What is a band within a band?

Answer 1

The idea of a band within a band goes back to the swing era (1930s and '40s) when, either for musical, contractual or economic reasons, band leaders issued recordings of (and/or devoted portions of live performances to) the core rhythm section (piano, bass, drums) and one or two front line instruments, to form a smaller and often jazzier (that is to say more improvisatory) group. This was in contrast to their full big bands which typically had in the region of 17 to 20 players, and required more in the way of arrangement. Such examples might be Tommy Dorsey's Clambake Seven, the Benny Goodman small groups, Bob Crosby's Bobcats, Count Basie's Smith-Jones Incorporated and Artie Shaw's Gramercy Five.

A band within a band can be a side project that any member of one band may do during the "low" times of the first bands production. Examples include: The Almost, made from the drummer of the band Underoath; and Nick Jonas and the Administration, from nick Jonas of the Jonas brothers.