Song the man rewrote (6)
I believe the answer is:
anthem
'song' is the definition.
(anthem is a kind of song)
'the man rewrote' is the wordplay.
'rewrote' indicates an anagram (I've seen 'rewritten' mean this).
'the'+'man'='theman'
'theman' anagrammed gives 'ANTHEM'.
(Other definitions for anthem that I've seen before include "One for doomed youth" , "Solemn song" , "The man for a rousing song" , "Hymn of loyalty" , "Church choral piece" .)