The horn is a brass instrument consisting of about 12–13 feet (3.7–4.0 m) of tubing wrapped into a coil with a flared bell. A musician who plays the horn is called a horn player (or less frequently, a hornist).
Descended from the natural horn, the instrument is often informally known as the French horn. However, this is technically incorrect since the instrument is not French in origin, but German. Therefore, the International Horn Society has recommended since 1971 that the instrument be simply called the horn. French horn is still the most commonly used name for the instrument in the United States.
Early horns were less complex than modern horns, consisting of brass tubes with a slightly flared opening (the bell) wound around a few times. These early "hunting" horns were originally played on a hunt, often while mounted, and the sound they produced was called a recheat. Change of pitch was effected entirely by the lips (the horn not being equipped with valves until the 19th century). Without valves, only the notes within the harmonic series are available. The horn was used, among other reasons, to call hounds on a hunt and created a sound most like a human voice, but carried much farther.
In orchestral settings, the horn (or, more often, pairs of horns) often invoked the idea of the hunt, or, beginning in the later baroque, determined the character of the key being played or represented nobility, royalty, or divinity.