Sound of my army band? (5)
I believe the answer is:
corps
'army band?' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for corps that I've seen before include "Large army group" , "ballet group" , "Branch of an army" , "Body of men" , "Large body of troops" .)