Finally! Music diva learns perfect pitch (4)
I believe the answer is:
cast
'pitch' is the definition.
(thesaurus)
'finally music diva learns perfect' is the wordplay.
'finally' suggests the final letters.
The last letters of 'music diva learns perfect' are 'CAST'.
(Other definitions for cast that I've seen before include "Team of actors in a play" , "Shy - group of actors" , "Character" , "Get rid of" , "Dramatis personae" .)