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
Tuba second harmonic (an octave higher than the fundamental). These alternative resonances are often known as false tones or privileged tones. Adding the six semitones provided by the three valves, these alternative resonances let the instrument play chromatically down to the fundamental of the open bugle (which is a 29 Hz B). The addition of valves below that note can lower the instrument a further six semitones to a 20 Hz E. Thus, even three-valved instruments with good alternative resonances can produce very low sounds in the hands of skilled players; instruments with four valves can play even lower. The lowest