Achieving success with the orchestration (7)
I believe the answer is:
scoring
This clue is a double definition.
'achieving success' is the first definition.
'the orchestration' is the second definition.
'with' is the link.
(Other definitions for scoring that I've seen before include "Arranging music" , "Gaining points" , "Cutting - running" , "Winning points" , "Writing music" .)