A wind instrument, such as the French horn or the trombone, made of brass or other metal. Sound is produced through vibration of the lips and adjustment of the length of the sound tube by means of valves or a slide. Musical wind instrument, usually made of brass or other metal, in which the vibration of the player's lips against a cup-or funnel-shaped mouthpiece causes the initial vibration of an air column. The trumpet, trombone, French horn, tuba, euphonium, sousaphone, cornet, flügelhorn, and bugle, as well as historical instruments such as the ophicleide, cornett, and serpent, are considered brass instruments (though the last two were made of wood); the saxophones, though made of brass, are reed instruments classified as woodwind instruments