French horn

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. A musician who plays any kind of horn is generally referred to as a horn player (or less frequently, a hornist).

Pitch is controlled through the combination of the following factors: speed of propulsion of air through the instrument (controlled by the player's lungs and thoracic diaphragm); diameter and tension of lip aperture (controlled by the player's lip muscles—the embouchure) in the mouthpiece; plus, in a modern French horn, the operation of valves by the left hand, which route the air into extra sections of tubing. Most horns have lever-operated rotary valves, but some, especially older horns, use piston valves (similar to a trumpet's) and the Vienna horn uses double-piston valves, or pumpenvalves. The backward-facing orientation of the bell relates to the perceived desirability to create a subdued sound, in concert situations, in contrast to the more piercing quality of the trumpet. A horn without valves is known as a natural horn, changing pitch along the natural harmonics of the instrument (similar to a bugle). Pitch may also be controlled by the position of the hand in the bell, in effect reducing the bell's diameter. The pitch of any note can easily be raised or lowered by adjusting the hand position in the bell.