The Queen entertaining a composer, a money-maker (6)
I believe the answer is:
earner
'a money-maker' is the definition.
(earner can mean a profitable scheme)
'the queen entertaining a composer' is the wordplay.
'the queen' becomes 'ER' (Elizabeth Regina).
'entertaining' indicates putting letters inside.
'a composer' becomes 'arne' (I've seen this before).
'er' going around 'arne' is 'EARNER'.
(Other definitions for earner that I've seen before include "lucrative job" , "Employee" , "The one who brings home the money" , "dubious money-making scheme" , "Money-making activity" .)