- Clifford Bevan
A valved brass instrument of wide conical bore. The tubing is usually coiled into an elliptical shape and terminates in a wide bell (usually pointing upwards) and a deep, cup-shaped mouthpiece. The instrument has an open fundamental of 8′ C (or lower) and is equipped with three to six (usually four, rarely seven) valves to alter the length of the tubing and hence the pitch. It is generally used in jazz as the bass or contrabass member of the band.
A group of related instruments, in various shapes and sizes, may be said to constitute a tuba family; its members are known generically as brass bass. The most important are the euphonium (sometimes referred to, especially in the USA, as the baritone horn, see Saxhorn (jazz)), which is essentially a tenor tuba in B♭; and the helicon and sousaphone, which are both types of bass tuba distinguished from the rest of the family by their circular shape. The lower members of the saxhorn group are also sometimes regarded as forming part of the tuba group. The sousaphone, named after the composer and bandmaster John Philip Sousa, is used mainly in marching bands. Like the helicon (now almost obsolete, but used by Rich Matteson on recordings by Bob Scobey’s Frisco Jazz Band in the 1950s and 1960s), it encircles the player, resting on the left shoulder and passing under the right arm, with the bell pointing forwards above the player’s head; this form was devised to facilitate carrying the instruments while marching. Some upright tubas have been made with the bell facing forwards; this “recording” bell was introduced during the 1920s, when the tuba often substituted for the double bass in recording studios....