Squeezebox (9)
I believe the answer is:
accordion
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">squeezebox</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for accordion that I've seen before include "Agreement starts the musical instrument" , "Cad I croon about a musical instrument" , "Squeeze-box" , "Free-reed aerophone" , "Bellows-operated instrument" .)