Orchestra deployed beast of burden (9)
I believe the answer is:
carthorse
'beast of burden' is the definition.
(I've seen this before)
'orchestra deployed' is the wordplay.
'deployed' indicates an anagram.
'orchestra' anagrammed gives 'CARTHORSE'.
(Other definitions for carthorse that I've seen before include "Beast of burden" , "has pulling power" , "large drawer" , "Equine" .)