Sunrise song (6)
I believe the answer is:
aubade
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sunrise song</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for aubade that I've seen before include "Piece of music appropriate to the dawn" , "piece of early music" , "Dawn music or poem" , "Morning song" , "early composition" .)