The trombone is the only instrument in the brass family that uses a slide instead of valves to change pitch. A standard trombone is made of long thin brass pipes. Two U-shaped pipes are linked at opposite ends to form an "S." One pipe slides into the other so the total length of the pipe can be extended or shortened. You play the trombone by holding it horizontally, buzzing into the mouthpiece, and using your right hand to change pitch by pushing or pulling the slide to one of seven different positions. If you stretch the trombone out straight, it is about 9 feet long. There are usually 3 trombones in the orchestra and they play pitches in the same range as the cello and bassoon. The three trombones often play harmonies together.