The french horn has a rich full sound that is used for melodic passages as well for providing accompaniment to other sections of the band. There are usually 3 or 4 differnt horn parts that are usally played with one-on-a-part.
A horn is an instrument consisting of a mouthpiece and a long tube that widens out to the bell. Along with the French horn pictured here the horn family includes such oddities as the Wagner Tuba and the Shofar (which you would never see in a concert band). The French horn is a brass instrument built in a circle, with a large bell that is held down by the player's side. It is also the only brass instrument in which the valves are operated with the left hand -- all other brass instruments are operated with the right hand. Its rich, velvety sound is heard mostly in orchestras and bands. The French horn first came into the orchestra in pairs to portray the sound of hunting horns but is now used in music of all sorts. The pitch range is three-and-a-half octaves, and its length is variable. The total length of unwound tube is between 9 and 12 feet. French horns are tranposing instruments and usually play in the key of F.