A brass instrument is an aerophone^[1] that is operated by lip movement (buzzing lips). The term 'brass instrument' is really a nickname. A more proper term is labrosone^[2], literally meaning 'lip sound'. An instrument made out of brass is not necessarily a brass instrument. For example: even though a saxophone is usually made out of brass, it is NOT a brass instrument. An instrument can be made out of materials other than brass and still be a brass instrument. For example: a trumpet made entirely out of plastic is still a brass instrument.