Horn

The Horn is a brass instrument made of tubing
wrapped into a coil with a flared bell.
Pitch is controlled by: speed of air through
the instrument; diameter and tension of lip
aperture in the mouthpiece; plus, 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 use
piston valves or double-piston valves.