EUPHONIUM. A modern band wind instrument. It has three or more valves or pistons with a slightly larger bore than the B b baritone horn. The euphonium is pitched an octave lower than the B b cor net and has an effective range of nearly three octaves. The tone is produced by a cup mouthpiece and the tension of the player's lips. The instrument is some times built with a tenor bell operated by an extra valve or piston. The bore of this bell has the dimensions and gives the same quality of tone as a trombone or tenor horn. When the player presses this extra valve the entire voice or tone qual ity of the instrument is changed. The euphonium is an important instrument in either the military or concert band, tak ing a part similar to that of the cello in the concert orchestra. The use of the tenor bell is optional. Many euphoniums are equipped with a fourth valve to facili tate fingering and to enable the player to get the complete chromatic scale to the fundamental or pedal note of the instrument.