Playing duet with horns, possibly aimed too low (9)
I believe the answer is:
undershot
'aimed too low' is the definition.
I can't judge whether this defines the answer.
'playing duet with horns' is the wordplay.
'playing' is an anagram indicator.
'with' is a charade indicator (letters next to each other).
'duet' after 'horns' is 'hornsduet'.
'hornsduet' with letters rearranged gives 'UNDERSHOT'.
'possibly' acts as a link.
Can you help me to learn more?
(Other definitions for undershot that I've seen before include "having missed target" , "with jutting jaw" , "landed short of runway" .)