The euphonium is a valved instrument; nearly all current models are piston valved, though rotary valved models do exist. As a tenor/baritone-voiced brass instrument, the euphonium traces its ancestry to the ophicleide and ultimately back to the serpent.
Professional models have three top-action valves, played with the first three fingers of the right hand. Though the euphonium’s fingerings are no different from those of the trumpet or tuba, beginning euphoniumists will likely experience significant problems with intonation, response, and range compared to other beginning players.
A person who plays the euphonium is sometimes called a euphoniumist, euphophonist, or a euphonist, while British players often colloquially refer to themselves as euphists, oreuphologists. Similarly, the instrument itself is often referred to as eupho or euph.