Tenor horn horn is a valved brass instrument (in E) which has a predominantly conical bore like the baritone horn and flugelhorn. It uses a deep funnel- or cup-shaped mouthpiece. The tenor horn's conical bore and deep mouthpiece produce a mellow, rounded tone which is often used as a middle voice, supporting the melodies of the trumpets, cornets or flugelhorns, and filling the gap above the lower tenor and bass instruments (the trombone, baritone horn, euphonium and tuba). Its valves are typically, though not exclusively, piston valves. The tenor horn has been made and is made in various shapes: the most common
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.