Instrument related to the cor anglais (4)
I believe the answer is:
oboe
'instrument related to the cor anglais' 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 "Orchestral instrument" , "Producer of notes" , "issuer of notes" , "Instrument used in 1d" , "music producer" .)