Novice’s ecofriendly producer of notes (9)
I believe the answer is:
greenhorn
'novice's' is the definition.
(greenhorn is a kind of novice)
'ecofriendly producer of notes' is the wordplay.
'ecofriendly' becomes 'green' (I've seen this before).
'producer of notes' becomes 'horn' (horns produce musical notes).
'green'+'horn'='GREENHORN'
(Other definitions for greenhorn that I've seen before include "Gullible type" , "colt" , "Raw, inexperienced youth" , "One learning" , "One's not experienced" .)