They produce sound body parts (6)
I believe the answer is:
organs
'body parts' is the definition.
(organ is a kind of body part)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for organs that I've seen before include "Periodicals published by special interest groups" , "Functional units in the body" , "Air-powered keyboard instruments" , "Keyboard instruments and body parts" , "Heart and lungs are vital ones" .)