About TromboneThe trombone is a musical instrument in the brass family. As on all brass instruments, sound is produced when the player's vibrating lips (embouchure) cause the air column inside the instrument to vibrate. Nearly all trombones have a telescoping slide mechanism that varies the length of the instrument to change the pitch. Many modern trombone models also use a valve attachment to lower the pitch of the instrument. Variants such as the valve trombone and superbone have three valves similar to those on the trumpet.