The duck in "Peter and the Wolf" (4)
I believe the answer is:
oboe
'the duck in peter and the wolf' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for oboe that I've seen before include "Double-reeded woodwind instrument" , "Orchestral piece" , "Orchestral instrument" , "issuer of notes" , "music producer" .)