Musical about orphan receives one award (7)
I believe the answer is:
olivier
'one award' is the definition.
The definition suggests a singular noun which matches the answer.
'musical about orphan receives' is the wordplay.
'musical' becomes 'oliver' (musical based on Oliver Twist).
'about orphan' becomes 'i' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'receives' means one lot of letters goes inside another.
'oliver' enclosing 'i' is 'OLIVIER'.
Can you help me to learn more?
(Other definitions for olivier that I've seen before include "English actor, first artistic director of the National Theatre" , "Laurence -, English actor and director" , "Great English actor playing rilievo" , "English actor best known for his Shakespearean roles" , "Classical actor" .)