Musical setting for Mamma Mia!, from the soundtrack? (6)
I believe the answer is:
grease
'musical' is the definition.
(Grease is a film musical)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for grease that I've seen before include "Lubricate - musical" , "Rock musical" , "Thick lubricant or frying oil" , "Musical - lubricant" , "Fatty lubricant" .)