Short operatic piece (7)
I believe the answer is:
arietta
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">short operatic piece</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for arietta that I've seen before include "Short operatic air" , "Short operatic song" , "Little song" , "Short operatic number" , "number from opera" .)