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
Tuba that the fundamental would be missing entirely, and would only be inferred from the overtones. However, the node and the antinode collide in the same spot and cancel out the fundamental. The tuba is generally constructed of brass, which is either unfinished, lacquered or electro-plated with nickel, gold or silver. Unfinished brass will eventually tarnish and thus must be periodically polished to maintain its appearance. Some tubas are capable of being converted into a marching style, known as "marching tubas". A leadpipe can be manually screwed on next to the valves. The tuba is then usually rested on the left