Musical skill
I believe the answer is:
ear
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">musical skill</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 ear that I've seen before include "Lug (colloq.)" , "See 24" , "Auditory organ" , "That makes sense" , "Shell-like; corn" .)