To make the Hexachord playable by a single person, I put knobs all along one side to control the individual sound chambers. Each knob was attached to a dowel that ran through the frame of the instrument to a scotch yoke mechanism, converting rotary to reciprocating motion. The scotch yoke mechanisms attached to ball and socket joints on the back of each sound chamber, allowing them to pivot on their wooden hinges, and move the strings in or out of the way of the spinning plectrum arm.