Simulated Chance and Staggered Gear Ratios

Sound examples and images related to this article are available at <www.marcberghaus.com>.

One of my primary artistic activities has long been to create mechanical representations of chance, to try to capture the incredibly complex non-linearity of the world around us using only very linear, 19th-century, Newtonian technology—brass gears, motors, hand-built crankshafts.

My artwork has always been concerned with chance, and human perceptions of causality, but I had initially employed more symbolic depictions of these phenomena, such as small, mechanized dioramas, or dice as a symbol of chance. In the late 1990s, I discovered several sources that would expand my outlook on random and semi-random processes, among them James Gleick's Chaos and Brian Eno's Year with Swollen Appendices, in which he writes about Steve Reich's early tape works and his own "Generative Music."

I thought that such processes—the overlapping of several simple elements to achieve complexity—would be an excellent way to actually incorporate chance, or at least perceived chance, into my own artwork, rather than just symbolizing it—and it was only a matter of combining simple mechanical systems rather than designing new, complex machines.

I began using these systems in two visually oriented pieces, Mandala #2 (2000) and Haiku Machine (2002). In Mandala #2, 16 dice, arranged in a grid under a bell jar, all roll at different speeds, powered by one motor hidden under the base (see cover of this issue of LMJ). Due to my use of unusual gear ratios (say, 1:1.7, rather than 1:2) in the gears that connect the drive shafts to the dice's axles, very few of the cycles line up again at once, and it becomes impossible to predict the patterns of all the tumbling dice, despite the fact that all actual randomness has been stripped from them. Haiku Machine works in a similar way, but uses three rows of motorized paper spools, each with six words printed around them, constantly rolling at different speeds. Six words per spool times nine spools produces 10,077,696 haiku.

For my first sound sculpture, I decided to use these same methods again. Randomized Red Piano (2005) (Fig. 21) is a tiny, worn toy piano, which I mounted atop a tall tower to fetishize it to a degree. It has 10 keys, all producing miserably tinny sounds. In the base, four motors turn 10 small crankshafts, each at a different speed, which then raise the long "pull-rods" that latch onto spring-powered levers at the top, which when released strike the keys.

The gear ratios for this piece were chosen to be truly randomizing. The drive shaft gears have either 21 or 23 teeth, while the crankshaft gears, with which they mesh, all have even numbers of teeth. This produces such ratios as 1:1.391, 1:1.417, 1:1.714 . . . Since the motors turn at a slow 1 rpm, it will take an incredibly long time for the cycles of all 10 gears to come back and line up the same again. The viewer/listener is extremely unlikely to hear the same sequence twice, and interesting moments do occur: randomized chords; arpeggios.

Although I am working on several new installations using digital randomizers, I do have two more mechanized pieces in the works. Crawling Clavichord is a slow-moving "cart" of 20 piano hammers from a salvaged piano, semi-randomly striking a row of 20 wires strung tightly across a gallery. The cart travels along on sprocket chains strung on either side of the wires, and the wires have guitar pickups and amplifiers on both ends. As the motorized cart slowly crosses the room, the tones and overtones on each side of the cart's hammers change. The cart then reverses itself after bumping into either wall.

Fig. 21.

Randomized Red Piano, 2005.

© Marc Berghaus. Photo © Doug Koch

My other staggered gear piece is titled Randomized Gregorian Piano and is somewhat similar to the Red Piano. However, this machine is designed to be installed onto the keys of an already existing grand...