1 Type of bass brass instr. played in vertical position in contrast to horizontal position of tpt., tb., etc. Term covers several kinds of brass‐band instr., e.g. euphonium, but term tuba usually means the standard orch. bass tuba in F (invented 1835) with compass from f an octave below bass clef upwards for about 3 octaves. Vaughan Williams comp. a conc. for bass tuba, 1954. There is a French 6‐valve tuba which can cover four octaves and play Wagner contrabass parts. The contrabass tuba has become standard in orchestras since the 1940s, where it is known as the ‘double C’ (CC) tuba. This is a whole tone higher than the ‘double B♭’ (BB♭), with either 3 or 4 valves, which is generally used in bands. Most of tuba family are of semi‐conical bore, with from 3 to 5 valves, and cup mouthpiece. The tenor tuba is rare, but is required by Strauss in Don Quixote, and in Brit. is identical with euphonium. Brass and military band tubas, sometimes called ‘basses’, are in E♭ (same as double‐bass tuba). See also sousaphone and Wagner tuba.
2 Sonorous organ stop, like trumpet, 8′, 16′, or 4′ pitch.