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 valve by Heinrich Stölzel in 1815) was an early variety. The piston valve found in the majority of valved brass instruments was invented in 1838 and patented in 1839. They are sometimes called Périnet valves after their inventor, François Périnet. They work by diverting air obliquely through ports in the stock of the valve so that a loop of tubing is included in the air stream, lowering the pitch. The stock of the valve is cylindrical and moves up and down through a larger cylindrical casing. The rotary valve works using a short circular plug housed in a larger cylindrical casing.