The French horn (since the 1930s known simply as the horn in professional music circles) is a brass instrument made of tubing wrapped into a coil with a flared bell. The double horn in F/B♭ (technically a variety of German horn) is the horn most often used by players in professional orchestras and bands, although the descant and triple horn have become increasingly popular. A musician who plays a horn is known as a horn player or hornist.
Pitch is controlled through the combination of the following factors: speed of air through the instrument; diameter and tension of lip aperture (by the player's lip muscles—the embouchure) in the mouthpiece; plus, in a modern horn, the operation of valves by the left hand, which route the air into extra sections of tubing.