The saxophne - like many other instruments comes in an array of sizes. If the instruments in this picture were to scale you could really see an even bigger difference between the different sizes - from the soprano to the baritone. A bass sax is REALLY BIG. More instrument means a lower sound, and the vibration of the reed through its brass body gives a sax a much different sound than that of a brass instument like a trumpet or a horn. Thanks to polymers!