Famous piece of music finally performed (5)
I believe the answer is:
noted
'famous' is the definition.
(noted can mean well-known or famous)
'piece of music finally performed' is the wordplay.
'piece of music' becomes 'note' (I've seen this in another clue).
'finally' indicates one should take the final letters.
The final letter of 'performed' is 'd'.
'note'+'d'='NOTED'
(Other definitions for noted that I've seen before include "Remarkable" , "Wrote it down" , "Having renown" , "Like music" , "Indicated" .)