Composer butchers composition (8)
I believe the answer is:
schubert
'composer' is the definition.
(Franz Schubert, 1797-1828)
'butchers composition' is the wordplay.
'composition' is an anagram indicator (letters arranged or composed in a different order).
'butchers' anagrammed gives 'SCHUBERT'.
(Other definitions for schubert that I've seen before include "Famous man behind bars" , "Franz --, Viennese composer" , "Austrian composer, d. 1828" , "Lieder composer" , "Butchers (anag) - composer, d. 1828" .)