Shed American clears for some percussion (9)
I believe the answer is:
castanets
'some percussion' is the definition.
(thesaurus)
'shed american clears' is the wordplay.
'shed' becomes 'cast' (shed can mean to discard or cast off).
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'clears' becomes 'nets' (as in to make a net profit).
'cast'+'a'+'nets'='CASTANETS'
'for' acts as a link.
(Other definitions for castanets that I've seen before include "kitchen need?" , "Flamenco clappers?" , "Wooden percussion instrument" , "Clicking percussion instruments" .)