There is a small  button lit by a diode. It´s mounted on an arm that sticks out of the installation. This interface reminds one of s technical museum and the start button for the model railway. When the diode is lit the audience can press the button to start a music and al-Khowarizmis Mekaniske Orkester plays a suggestion for a music, as if to say, this can also be music, or, here's a way to organize light, sound and movement in a musical fashion.