Tuba , lowest-pitched of the brass wind instruments, with a wide conical bore, three or four valves, a deep cup-shaped mouthpiece, and vertically coiled tubing with an upward-pointing bell. It was one of several efforts to provide a suitable valved brass bass for the wind band. Its antecedents include the serpent (an S-shaped, cup-mouthpiece wooden bass with finger holes) and the ophicleide (a keyed bass bugle). The tuba has a compass of more than three octaves. It is normally built as a bass in E-flat or F (lowest sounding note: second B-flat or second C below middle C) or as a contrabass in B-flat or C (lowest sounding note: second E-flat or second F below middle C). The B-flat contrabass is sometimes known as the ΓÇ£double B-flatΓÇ¥ tuba. A tuba with circular coiling is a helicon; the sousaphone is a variety of helicon. Wagner tubas are four-valve instruments with a narrower bore, designed for the German composer Richard Wagner.
