Cheerful tune
I believe the answer is:
lilt
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">cheerful tune</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 lilt that I've seen before include "Characteristic voice rhythm; Scots tune" , "Sing happily" , "Swing - music" , "Cheerful tune" , "Gentle rhythm (in tune)" .)