He gives a variation of the rondo (5)
I believe the answer is:
donor
'he gives' is the definition.
(I've seen this before)
'a variation of the rondo' is the wordplay.
'a variation of' is an anagram indicator (I've seen 'variation' mean this).
'rondo' is an anagram of 'DONOR'.
(Other definitions for donor that I've seen before include "Maker of gift" , "One who gives, perhaps blood" , "One who dishes out" , "Subscriber" , "Supporter" .)