Tuba rotary-valved tubas pitched in the same octave as euphoniums. The "Small Swiss Tuba in C" is a tenor tuba pitched in C, and provided with 6 valves to make the lower notes in the orchestral repertoire possible. The French C tuba was the standard instrument in French orchestras until overtaken by F and C tubas since the Second World War. One popular example of the use of the French C tuba is the "Bydło" movement in Ravel's orchestration of Mussorgsky's "Pictures at an Exhibition", though the rest of the work is scored for this instrument as well. Larger BBB subcontrabass
Brass instrument valve Brass instrument valve Brass instrument valves are valves used to change the length of tubing of a brass instrument allowing the player to reach the notes of various harmonic series. Each valve pressed diverts the air stream through additional tubing, individually or in conjunction with other valves. This lengthens the vibrating air column thus lowering the fundamental tone and associated harmonic series produced by the instrument. Valves in brass instruments require regular maintenance and lubrication to ensure fast and reliable movement. The first piston-valved musical instruments were developed just after the start of the 19th century. The Stölzel valve (invented