Granular Wall
Saturday, Jan. 30, 11 a.m.–4 p.m.
Sunday, Jan. 31, 1–4 p.m.
Morehead Planetarium
250 E. Franklin St., Chapel Hill

Perhaps we looked ridiculous, standing there on a Sunday afternoon in an art museum, pushing the black cups of headphones fast and firm against our ears and staring, like children in a funhouse, at a frozen, glowing orb of ice.

But every few moments, someone else in the room would guffaw and smile, passing a hand over a mouth and turning to a neighbor to seek reassurance as to what exactly was heard. Was it a pyloric gurgle or a seismic splinter? A minuscule pop or maybe a major splatter? They were all the astonishing sounds of melting ice.

That installation, in January 2013 at UNC-Chapel Hill’s Ackland Art Museum, was Cryoacoustic Orb, the second major project of the two-composer team that calls itself the Portable Acoustic Modification Laboratory. Together, UNC professor Lee Weisert and his longtime collaborator Jonathon Kirk stage counterintuitive, deep listening experiences, where the audience is forced to reconsider the acoustics of the surrounding world, or to search for signals in spaces assumed to hold only noise. This weekend, they’ll follow Cryoacoustic Orb with Granular Wall, an attempt to turn the psychedelic spectacle of a 16-square-foot tank filled with thousands of glowing polyethylene balls into a continuous symphony of pointillist sound.

“We’re trying to use technology to extract music materiallike with the iceor musical form from the environment,” says Weisert. “It has enough direct engagement with nature, we hope, that it’s very easy to comprehend.”

Since meeting in Northwestern’s doctoral composition program almost a decade ago, Weisert and Kirk have worked to translate natural, pedestrian environments into immersive musical events. For their first major piece, 2008’s The Argus Project, the pair submerged hydrophonesthat is, microphones meant for underwater recordingin a pond on the campus of Eastern Illinois University, where Kirk was teaching. They recorded the aquatic activities and processed them through audio software controlled by data about the day, like the time or the light availability or the temperature. Depending on the conditions around the pond, the software would then manipulate the frequencies, filters and reverb levels and route the results through an array of speakers surrounding the pond.

“The idea was to turn the pond, or any general environment, into both the sound source and the ‘performer,’ the source of the alterations to the sound source,” says Weisert. “During that first performance, we drew audience members in who weren’t even looking for it. They were just intrigued by these strange sounds coming from the speakers by the pond.”

Granular Wall, though, moves the activity indoors into a room that can be effectively blacked out. That’s the only way the sophisticated setup works. Weisert and Lee filled a tank resembling a large flat-screen television with buoyant bubbles and programmed four jets to push them in specific patterns and sequences. With the lights off, and against an ultraviolet background, the bubbles glow, moving in mesmerizing shapes like schools of bioluminescent organisms. Computer software analyzes that motion and, through the process of granular synthesis, interprets it as music.

The output is surprisingly whimsical, with tiny, bright bits of tonessometimes quick and pulsing, other times slowed to something like a short glissando slurppercolating in an otherwise silent space. It’s like the sound of rain on a tin roof reimagined for an Atari video game, or a hypothetical Morton Subotnick score for a Planet Earth portrayal of an ant colony.

Granular Wall from Lee Weisert on Vimeo.

This isn’t a one-to-one relationship, where the sounds portray each of the particles. Instead, the space between the two senses engages the audience.

“With visuals, you can take in everything all at once. With sound, our eardrums are in and out, and you can only handle one source of information at a time,” Weisert says. “I don’t think it’s possible to create a soundscape where we can comprehend the intricacies of the visual corollary. Connecting the dots between the music and the visuals can be done with the imagination.”

For Weisert and Kirk, these compositions tax the imagination. They evolve quickly into technical challenges, with series of engineering problemsand searches for solutionsstanding between the infant idea and actual execution. In building Granular Wall, for instance, the composers had to learn about robotics in order to operate the jets that move the balls. They studied acrylic strengths and weights in order to determine how large the tank could be, and they consulted with Angus Forbes, a professor within the University of Chicago’s pioneering Electronic Visualization Laboratory, about how to turn so many indistinguishable sights into discrete sounds. They’d accidentally brushed up against one of the most vexing issues of motion tracking. The complicated solution, Weisert admits, was Granular Wall‘s real breakthrough.

Even when I ask him about the fluid in the tanks, Weisert confirms that it’s not just water. They’ve added a little bit of chlorine to prevent the balls and tank from growing gross over time, like a backyard pool left standing over winter.

But it’s worth the trouble, he thinks, to produce an environment that captivates the senses with two distinct outputssound and sightderived from the same radiant source.

“You’re looking at a giant tank with 10,000 lights hovering in it,” he says. “That’s always been the unspoken goal with any of our projectsto create a situation that is overwhelming, that you can just experience on a noncerebral level. We want to create objects of wonder.”

This article appeared in print with the headline “Floating action”