Sound organ composition (5)
I believe the answer is:
groan
'sound' is the definition.
(I have seen 'Sound of despair ' mean 'groan' so perhaps 'sound' could also mean 'groan')
'organ composition' is the wordplay.
'composition' indicates an anagram.
'organ' with letters rearranged gives 'GROAN'.
(Other definitions for groan that I've seen before include "Complain" , "Express disappointment, pain" , "Complaint" , "Titus -- (Mervyn Peake)" , "See 18 Down" .)