Measure is a piece by David Rokeby in which an analogue clock in the middle of a room has its ticking run through a processor that affects its acoustic behavior based on the viewer’s movements. This is a variation of his previous piece, Very Nervous System, which used the participants movements to synthesize different sounds rather than change the acoustic behavior of a virtual space. I think this approach is much more interesting because it activates the space much more–rather than encouraging the viewer to move around to try to activate the program, it gives the illusion that they are actually interacting with the physical object. The effect is quite mystical as the clock, which is already symbolic of the interaction of time and space, becomes powerful. This is because the digital aspects are hidden, only an intermediate aspect of the piece that facilitates an interaction between the viewer and a real object. It is also made more believable because the only sound comes from the real-time ticking and its feedback.