Musical pitch symbol (4)
I believe the answer is:
clef
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">musical pitch symbol</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 clef that I've seen before include "Musical pitch indicator" , "Item of musical notation" , "Symbol on the left of a musical stave" , "Musical stave sign" , "Musical pitch notation" .)