The trombone is a musical instrument in the brass family. As with all brass instruments, sound is produced when the player's lips vibrate inside a mouthpiece, causing the air column inside the instrument to vibrate. Nearly all trombones use a telescoping slide mechanism to alter the pitch instead of the valves used by other brass instruments. The valve trombone is an exception, using three valves similar to those on a trumpet, and the superbone has valves and a slide.