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
British brass band horns, which are found in orchestras and concert bands. The standard instrumentation is as follows: The above totals 27–29 players, although in practice a band often has fewer than this. Spare seats may be filled for concerts and contests by players brought in from other bands, commonly known as "deputising players" or "deps". With the exception of percussion, bass trombone and some tenor trombone music, all parts are transposing and written in the treble clef with the instrument's lowest open note (B♭ or E♭) notated as middle C. This means that for every valved instrument, from the basses to the