Diva's tune (4)
I believe the answer is:
aria
'diva's tune' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for aria that I've seen before include "Song such as "Your Tiny Hand is Frozen"" , "Imitative art work" , "Operatic tune" , "Summertime perhaps" , "Refrain" .)