Brass family instruments produce their unique sound by the player buzzing his/her lips while blowing air through a cup- or funnel-shaped mouthpiece. To produce higher or lower pitches, the player adjusts the opening between his/her lips. The mouthpiece connects to a length of brass tubing ending in a bell. The shorter the tubing length, the smaller the instrument, and the higher the sound; and the longer the tubing length, the larger the instrument, and the lower the sound. The brass family can trace its ancestry back to herald trumpets, hunting horns, and military bugles. The main instruments of the brass family include the trumpet, horn, trombone, and tuba.
The mouthpiece of the trombone is larger than that of a trumpet, and gives the instrument a more mellow sound. Instead of valves, the trombone has a slide which changes the length of its approximately 9 feet of tubing to reach different pitches.