Hard worker on the edge for song (6)
I believe the answer is:
anthem
'song' is the definition.
(anthem is a kind of song)
'hard worker on the edge' is the wordplay.
'hard worker' becomes 'ant'.
'on' is a charade indicator (letters next to each other).
'the edge' becomes 'hem' (I've seen this before).
'ant'+'hem'='ANTHEM'
'for' acts as a link.
(Other definitions for anthem that I've seen before include "National hymn" , "Solemn song" , "One for doomed youth" , "Song in praise of a nation" , "National or religious song" .)