Record some film music (5)
I believe the answer is:
score
I believe this clue is a double definition.
'record' is the first definition.
(I know that score is a more specific form of the action record)
'some film music' is the second definition.
(I've seen this in another clue)
(Other definitions for score that I've seen before include "purchase of illegal drugs" , "Grade; twenty" , "Points in a match" , "Orchestrate; twenty" , "Group of 20" .)