A brass band instrument is a type of musical instrument made of brass and used in a brass band. The most common brass band instruments are the TUBA (4 letters), euphonium (9 letters), and slide trombone (13 letters). The TUBA is a large, low-pitched brass instrument that produces a deep sound. The euphonium is a medium-sized brass instrument with a mellow tone. The slide trombone is a brass instrument with a slide that is used to change the pitch of the notes.