Instrument to cut branches? Sharpen axes first (9)
I believe the answer is:
xylophone
'instrument' is the definition.
(I know that xylophone is a type of percussion instrument)
'cut branches? sharpen axes first' is the wordplay.
'cut branches?' becomes 'lop' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'sharpen' becomes 'hone' (honing is a kind of sharpening).
'axes' becomes 'xy' (x axis and y axis).
'first' is a charade indicator (letters next to each other).
'lop'+'hone'='lophone'
'lophone' put after 'xy' is 'XYLOPHONE'.
'to' is the link.
Can you help me to learn more?
(Other definitions for xylophone that I've seen before include "Musical instrument with bars" , "Percussion instrument with wooden bars" , "Instrument with wooden bars to be struck" , "Patrick Moore's instrument" , "Percussion instrument played with mallet" .)