Portion; musical work (5)
I believe the answer is:
piece
I believe this clue is a double definition.
'portion' is the first definition.
(I know that piece is a type of portion)
'musical work' is the second definition.
(synonyms)
(Other definitions for piece that I've seen before include "Scrap - musical work" , "man on board" , "Single article" , "Chessman; portion" , "Unpleasant character" .)