tubas

The tuba is the largest and lowest-pitched brass instrument. It forms the bass foundation in many ensembles, including orchestras, concert bands, brass bands, and most marching bands. Tubas are typically valved brass instruments with a long conical bore, a large flared bell, and a mouthpiece. Sound is produced by buzzing the lips into the mouthpiece, with pitch and timbre altered by the valve combinations and the length of tubing. Modern tubas are usually pitched in BBb or F, though orchestral models can be in C or E-flat. They come in several sizes, such as bass tuba and contrabass tuba, and some designs use rotary valves rather than piston valves. Most modern instruments have four valves, with five-valve configurations also used to extend the lower range.

The modern tuba emerged in the 1830s in Germany, where instrument makers developed the design to provide a reliable, portable low brass voice for military bands and, later, symphonic ensembles. The instrument quickly spread to other parts of Europe and North America and became a standard member of the brass section.

Common variants include the sousaphone, a marching-tuba wraparound designed by John Philip Sousa for loud projection and ease of carrying on the march; the concert or BBb/CC tubas used in classical settings; and double-bell or specialized contrabass models that appear in some contemporary works. Tubas are used across a range of genres, from classical to film scores and jazz, where they may supply a rhythmic bass line or a deep melodic foundation.