Horn in F

The Horn in F (ホルン) is a brass instrument. A musician who plays the horn is called a horn player (or less frequently, a hornist).

Construction
The instrument is made up of approximately 4 meters of tubing wrapped into a coil with a flared bell. The main tubing on an F horn is about 12–13 ft (3.7–4.0 m) long and that associated with the valves adds additional length to achieve up to about 17 ft (5.2 m) of tubing overall.

Performance
Pitch is controlled through the adjustment of lip tension in the mouthpiece and the operation of valves by the left hand, which route the air into extra tubing.

The player's right hand will rest in the bell of the instrument. This technique probably has to do something with the earlier valveless horns, whose pitch could be flattened by manipulating the right hand inside the bell.

Scoring
The double horn in F/B♭ is the horn most used by professional bands and orchestras.

As portrayed in Sound! Euphonium
There are five students that play horn in Kitauji High School Concert Band including:
 * Juri Sawada - 1st horn, horn section leader
 * Hiro Kahashi - 2nd horn
 * Michiyo Morimoto - 3rd horn
 * Miru Kishibe - 4th horn/Horn section leader (Our Promise)
 * Lala Hitomi

In Sound! Euphonium: The Movie - Our Promise: A Brand New Day, four new horn players join the ensemble:
 * Aine Kohara
 * Hibiki Tsuchiya
 * Sumiko Fukamachi
 * Sanae Yashiki

In addition, Noboru Taki played the horn in elementary and middle school before switching to the trombone.

Chihiro Taki, a wife of Noboru Taki, was also a horn player, and majored in horn in college.

Shuuichi Tsukamoto also played horn prior to high school, where he switched to trombone.

Trivia

 * The proper name of the horn is simply the horn, or horn in F. French Horn is a colloquial term for the instrument that is not officially recognized in the professional music world.
 * Horn instrumentation is written as "F Horn" in band music. Many people take this as an abbreviation of "French Horn," when in reality, the F means "key of F," since the horn is pitched in F as opposed to C.
 * In Sound! Euphonium, the horn section notably seems to change significantly from being laid-back and lazy to hardworking and serious over the course of the first season; they tend to be used as a showcase of how the band is becoming more determined and serious. As a result, they are arguably among the more well-developed secondary characters.
 * Horns seen in Sound! Euphonium are based on Yamaha YHR-567 Full Double model.