Romantic song (6)
I believe the answer is:
ballad
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">romantic song</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for ballad that I've seen before include "Song type" , "Folk song" , "Lay, narrative song" , "delivered by singer" , "Love song" .)