Part of the trombone: The three main parts of the trombone are the bell, slide, and mouthpiece. The mouthpiece is where the player blows air into in order to create the sound. The slide determines what note the player will play. The bell then releases the sound.
The Bass Trombone: bigger than the regular trombone and plays lower notes. Bass trombones are used for bigger sounds, and they are used to help enhance the tuba as well as the other trombones. Usually there is only one bass trombone in a band or an orchestra.