Inspired by the 13 century musical instrument, and working with the rhythm and tempo created by the human arm, the Shadow Organistrum tests interactive forms of virtual space. This device creates a continuously random link between the user, as they turn the lever, and the space that surrounds them. The installation puts into question the “reality” of the space found between the shadow surface and the focus, or source of light. Not sound, but shadows, “draw” the “musical” score, and the space surrounding the device.