The trumpet is a musical instrument with the highest register in the brass family. Trumpets are among the oldest musical instruments, dating back to at least 1500 BC. They are constructed of brass tubing bent twice into an oblong shape, and are played by blowing air through closed lips, producing a "buzzing" sound which starts a standing wave vibration in the air column inside the trumpet.

There are several types of trumpet; the most common is a transposing instrument pitched in Bmusic: flat. The predecessors to trumpets did not have valves; however, modern trumpets have either three piston valves or three rotary valves, each of which increases the length of tubing when engaged, thereby lowering the pitch.

The trumpet is used in many forms of music, including classical music and jazz.

History

Improvements to instrument design and metal making in the late Middle Ages and Renaissance led to an increased usefulness of the trumpet as a musical instrument. The natural trumpets of this era consisted of a single coiled tube, without valves. This only allowed for one overtone series at a time to be played. Changing keys required the player to swap out the crooks of the instrument. The development of the upper, "clarino" register by specialist trumpeters—notably Cesare Bendinelli—would lend itself well to the Baroque era, also known as the "Golden Age of the natural trumpet." During this period, a vast body of music was written for virtuoso trumpeters. The art was revived in the mid-20th century and natural trumpet playing is again a thriving art in Europe. The popularity of natural trumpets in the United States has waned considerably from its heyday in the 1960's and 70's.

The melody-dominated homophony of the classical and romantic periods relegated the trumpet to a secondary role by most major composers owing to the limitations of the natural trumpet. Berlioz wrote in 1844:
"Notwithstanding the real loftiness and distinguished nature of its quality of tone, there are few instruments that have been more degraded (than the trumpet). Down to Beethoven and Weber, every composer - not excepting Mozart - persisted in confining it to the unworthy function of filling up, or in causing it to sound two or three commonplace rhythmical formulae."
The attempt to give the trumpet more chromatic freedom in its range saw the development of the keyed trumpet, but this was a largely unsuccessful venture due to the poor quality of its sound.

The trumpet was slow to adopt the modern valves (invented around the mid 1830s), and its cousin the cornet would take the spotlight as solo instrument for the next hundred years. The symphonies of Mozart and Beethoven, even Brahms, were still played on natural trumpets. Crooks and shanks (removable tubing of various lengths) as opposed to keys or valves were standard, notably in France, into the first part of the 20th century. As a consequence of this late development of the instrument's chromatic ability, the repertoire for the instrument is relatively small compared to other instruments. The 20th century saw an explosion in the amount and variety of music written for the trumpet.