Darts back to get a violin (5)
I believe the answer is:
strad
'a violin' is the definition.
(Stradivari abbreviation)
'darts back' is the wordplay.
'back' says the letters should be written in reverse.
'darts' reversed gives 'STRAD'.
'to get' acts as a link.
(Other definitions for strad that I've seen before include "fiddle exposed" , "Famous violin" , "that Grappelli could have played" , "Top-quality violin (abbr.)" , "Valuable violin (abbrev.)" .)