Four voice Hohner 1055 musette piano accordion, with keyboard rebuild and complete re-valve and tune. Palm coupler on treble side for low/basoon octave reed. Musette here means three middle reeds tuned one slightly flat, one on concert and one slightly sharp, to give a rich ‘musette’ sound. Two voice accordions normally have one reed tuned to concert pitch and another reed tuned slightly sharp (or flat on older accordions).
Short clip here to hear the musette sound: