Work on historical period for musical production (5)
I believe the answer is:
opera
'musical production' is the definition.
(I've seen this in another clue)
'work on historical period' is the wordplay.
'work' becomes 'op' (abbreviation for opus).
'on' is a charade indicator (letters next to each other) (in a down clue, letters appear on others).
'historical period' becomes 'era' (I've seen this before).
'op'+'era'='OPERA'
'for' acts as a link.
(Other definitions for opera that I've seen before include "E.g. Macbeth, Falstaff" , "Verdi work?" , "art form" , "Eg, Il trovatore" , "Macbeth, say" .)