Butcher's order for a composer (8)
I believe the answer is:
schubert
'for a composer' is the definition.
(Franz Schubert, 1797-1828)
'butcher's order' is the wordplay.
'order' indicates anagramming the letters.
'butchers' anagrammed gives 'SCHUBERT'.
(Other definitions for schubert that I've seen before include "Lieder composer" , "Austrian composer, d. 1828" , "Famous man behind bars" , "Franz -, Austrian composer (Trout Quintet, etc)" , "Franz --, Viennese composer" .)