Orchestral instrument remains -- blow it! (12)
I believe the answer is:
fiddlesticks
'orchestral instrument remains blow it' is the definition.
I can't judge whether this defines the answer.
'instrument remains blow it' is the wordplay.
I cannot quite understand how this works, but
'instrument' could be 'fiddle' (fiddle is a kind of instrument) and 'fiddle' is located in the answer.
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is present in the answer.
The remaining letters 'sicks' is a valid word which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for fiddlesticks that I've seen before include "Bother!" , "Rhubarb" , "Bows - nonsense" , "Bilge" , "tripe" .)