A pocket trumpet is a small version of the regular or standard B flat trumpet commonly found in bands, orchestras and other ensembles. It is regarded more as a novelty instrument, so even though professional versions of high quality are available, most professionals do not use them for serious playing. This smaller instrument is desired mainly because its compactness provides ease in transport, which is useful in situations such as playing in a marching band.
This small trumpet is only 9.5 inches (24.13 cm) long, and is between 6.5 and 7 inches (16.51 cm and 17.78 cm) in height. Bore sizes vary but are comparable to those of the B flat trumpet. The small size of the instrument leads to people confusing it with the piccolo trumpet, which has half the tubing of a B flat trumpet and therefore plays one octave higher.
Manufacturers design pocket trumpets in two major ways: the first is to reduce both the bore and bell size. This usually isn't as desirable because the intonation and other musical elements such as timbre suffer. It also means that the musician cannot use a standard-size mute with the instrument, which greatly limits the styles and colors the player can produce. The second approach is to keep the bore and bell the same as the B flat trumpet, which solves the problems reducing the bore and bell create.
The range of the pocket trumpet is essentially the same as the standard B flat trumpet. Adept players thus easily can achieve the F sharp below middle C, or F3, at the bottom of the range. The upper range peaks about three octaves higher, or F6, with the ability to reach at least C5 standard for good players.
The pocket trumpet is able to produce the same basic range as the standard B flat trumpet because manufacturers use the same amount of tubing for the pocket trumpet as for the B flat trumpet. Pocket trumpets even use B flat trumpet mouthpieces. The only real difference is that manufacturers wind the tubing in a more compact fashion, thereby shortening the length of the instrument without sacrificing range. Although the pocket trumpet can play in the same range as the B flat trumpet, the fact it has more bends and curves in the tubing does make it a little more difficult to play in that there is greater air resistance, similar to a cornet. The tone also can be slightly mellower than a B flat trumpet, although many musicians describe the pocket trumpet's sound as more tinny.
In terms of quality, these instruments have a huge range. Some are little better than wall decorations, having extremely poor sound and intonation, but on the other end of the spectrum, professional-grade pocket trumpets easily can run into the thousands of dollars and have a response and color that rivals any high-quality B flat trumpet.