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
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