Highest singing voice (7)
I believe the answer is:
soprano
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">highest singing voice</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for soprano that I've seen before include "chorus girl, perhaps" , "High female voice" , "Woman singing" , "Producer of high-pitched sounds" , "Singer who aims high" .)