Brass instrument can be very useful for a 1st or 3rd horn player, who uses the F side less. Another approach was the addition of two sets of slides for different parts of the range. Some euphoniums and tubas were built like this, but today, this approach has become highly exotic for all instruments except horns, where it is the norm, usually in a double, sometimes even triple configuration. Some valved brass instruments provide triggers or throws that manually lengthen (or, less commonly, shorten) the main tuning slide, a valve slide, or the main tubing. These mechanisms alter the pitch of notes
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