Composers butcher Artemis (7)
I believe the answer is:
maestri
'composers' is the definition.
(plural of maestro)
'butcher artemis' is the wordplay.
'butcher' indicates anagramming the letters.
'artemis' anagrammed gives 'MAESTRI'.
(Other definitions for maestri that I've seen before include "Distinguished musicians" , "Top musicians" , "masters" , "Eminent musical conductors" , "Famous conductors" .)