Contributor performed rondo (5)
I believe the answer is:
donor
'contributor' is the definition.
(I've seen this before)
'performed rondo' is the wordplay.
'performed' indicates anagramming the letters.
'rondo' anagrammed gives 'DONOR'.
(Other definitions for donor that I've seen before include "Maker of gift" , "One giving something" , "patron" , "Sponsor" , "A giver, often of blood" .)