Composition for one (4)
I believe the answer is:
solo
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">composition for one</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 solo that I've seen before include "Alone - card game" , "Alone, unaccompanied" , "Type of whist" , "Unaccompanied passage" , "something for one to do" .)