Euphonium are the tuba-euphonium quartet or larger tuba-euphonium ensemble; the brass quintet, where it can supply the tenor voice, though the trombone is much more common in this role; and other mixed brass ensemble. Such ensembles are almost non-existent: they are more likely to be semi-professional or amateur in nature. Most of the United States Armed Forces service bands include a tuba-euphonium quartet made up of players from the band that occasionally performs in its own right. The euphonium is not traditionally an orchestral instrument and has not been common in symphony orchestras. However, there are a few works from the
Brass instrument almost universal by (at latest) 1864 as witnessed by Arban's Method published in that year. The effect of a particular combination of valves may be seen in the table below. This table is correct for the core 3-valve layout on almost any modern valved brass instrument. The most common four-valve layout is a superset of the well-established 3-valve layout and is noted in the table, despite the exposition of four-valve and also five-valve systems (the latter used on the tuba) being incomplete in this article. Since valves "lower" the pitch, a valve that makes a pitch too low (flat) creates