Squeezebox (9)
I believe the answer is:
accordion
'squeezebox' is the definition.
(I've seen this before)
This is all the clue.
(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" .)