Euphonium main tuning slide trigger, which allows players more flexibility with intonation. The euphonium, like the tenor trombone, is pitched in concert B. For a valved brass instrument like the euphonium, this means that when no valves are in use the instrument will produce partials of the B harmonic series. It is generally orchestrated as a non-transposing instrument like the trombone, written at concert pitch in the bass clef with higher passages in the tenor clef. Treble clef euphonium parts transposing down a major ninth are included in much concert band music: in the British-style brass band tradition, euphonium music is
Tuba of notes. Prior to the invention of valves, brass instruments were limited to notes in the harmonic series, and were thus generally played very high with respect to their fundamental pitch. Harmonics starting three octaves above the fundamental pitch are about a whole step apart, making a useful variety of notes possible. The ophicleide used a bowl-shaped brass instrument mouthpiece but employed keys and tone holes similar to those of a modern saxophone. Another forerunner to the tuba was the serpent, a bass instrument that was shaped in a wavy form to make the tone holes accessible to the player.