Protective cover for front of stage (5)
I believe the answer is:
apron
This clue is a double definition.
'protective cover' is the first definition.
(I've seen this before)
'front of stage' is the second definition.
(I've seen this before)
'for' is the link.
(Other definitions for apron that I've seen before include "Kitchen garment or airfield surface." , "skirt" , "Put on to protect" , "Kitchen garment or aerodrome strip" , "Paved surface where aircraft stand when not in use" .)