conductors' instruments (6)
I believe the answer is:
batons
'conductors' instruments' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for batons that I've seen before include "Conductors flourish them, or policemen" , "Conductors wield them - or policemen" , "Rods for conductors and coppers" , "With which to conduct" , "Rods for conductors and police" .)