How is a trombone sound changed?

The sound of a Trombone is altered primarily through the manipulation of its slide, which changes the length of the instrument's tubing and thus its pitch. By extending or shortening the slide, the player can access different notes and harmonics. Additionally, variations in embouchure (the way the player uses their lips) and air pressure can affect the tone quality and dynamics of the sound produced. These elements combined allow for a wide range of expressive capabilities in trombone playing.