Like the bells, trumpets are ancient instruments that have evolved over time to the gleaming instruments we now associate with Louis Armstrong and Dizzy Gillespie. The trumpet produces sound when air is forced through mouthpiece and into the instrument. Notes are played by the correct placement of the lips and by pressing or releasing valves that were the 19th Century innovation given to the instrument. The development of a "slide" which alters the length of the tube the air moves through gives the trumpet a broader range of sounds.
Hear a Trumpet