The music of another culture or era often gives listeners a perspective outside their own — but what about music from another species? Seeking insight into how spiders sense the world, researchers have transposed the complex structures of spiderwebs into listenable sounds for humans.
Presented on Monday during the spring meeting of the American Chemical Society, their research demonstrates that melodies and rhythms can be extracted from natural materials, such as a spider's silk, creating new possibilities for art, 3D printing and trans-species communication.
Lead researcher Markus Buehler, a professor of engineering at the Massachusetts Institute of Technology, has worked for years with Argentinian artist Tomás Saraceno to digitize 3D spiderwebs, scanning them with lasers and uploading them into a computer. Now, they've taken their research a step further by treating connections in spiderwebs as strings on an instrument.
"The idea was literal, to think of the spiderweb as a harp with many different strings," Buehler said in an interview with The Academic Times. "A spider lives in a universe of vibrations. They use vibrations to orient themselves."
Unlike other "sonification" experiments, in which researchers assign somewhat arbitrary pitches to movements in the stock market or Earth's atmosphere, Buehler's team stayed as true to the spider's sensory experience as possible — spiders have poor eyesight but are able to distinguish light and dark, and they use vibrations in their webs and on the ground to locate prey and mates. The scientists assigned frequencies to each string based on length and tension, resulting in pitches not found in the 12-tone scale of Western music. "The frequencies might be much lower, not in the audible range of a human, but we can transpose them," he said. "As long as we keep the ratios the same, we have continuity."
"We have a really accurate reflection of the structure and frequencies the spider feels," he added.
Sounds sourced from spiderwebs require a bit of translation for human audiences, however. Buehler pinpoints the frequencies of the Western tuning system within the web, filtering out the most amorphous, atonal noises to arrive at something more familiar-sounding.
"We can extract melodies," he said. "As you scan through the web, you can assign notes according to the closest frequencies you find and develop melodies. It's surprising, when you do that, to find aesthetically pleasing musical ideas in that weird web structure, to create some more human-sounding stuff."
The resulting music is strange and otherworldly yet occasionally groovy, complete with rhythms typically extracted from the web structure and hair-raising synthesized noises recalling the movements of a spider. (One track and accompanying video represent a spiderweb as it's stretched to its breaking point.)
Though a spiderweb might look random to us, Buehler found that patterns emerged as he analyzed the models. "If you look at a cobweb in your house, it looks like nothing in particular," he said. "But when you scan and analyze it, you find regions that are densely packed, almost like a lattice structure, and regions that are less dense. Musically, you can hear that."
On the outer reaches of the web, where there are few strands, the music is sparse and sounds out of tune. But the dense heart of the web sounds "monumental," Buehler said, as thousands of higher-tension strings vibrate together at strange frequencies, creating unexpected effects.
"The web is tuned by the spider to have certain tensions, but it's tuned according to what the spider wants to measure," he said. "Maybe they're measuring prey being trapped or finding other spiders that live in the same web or neighboring webs.
"To us, of course, it sounds out of tune, but for the spider that's the world she lives in," Buehler added. "That's her perfectly tuned universe."
Prior to COVID, the team had taken the show on the road. Isabelle Su, Buehler's graduate student and a co-author of the study, has performed the harp-like instrument onstage at the center of a massive web, accompanied by a guitarist and wind instrumentalists. "In the beginning, it sounds weird," Buehler said of the performances. "Then you spend a lot of time in that new tuning system and you get entranced, and it's this remarkable experience."
Aside from exploring new ways to compose and create sounds, Buehler also believes his team's research on spiderweb construction could help spur advancements in 3D printing. "Spiders are much better 3D printers than anything humans have created to date," he said. "There are lots of lessons we can learn about materials that self-repair. These spiderwebs are living ecosystems of materials that are very strong and continually repairing and adapting."
Buehler is exploring exciting opportunities for communication between humans and spiders as well. The next phase of his research will be attempting to play "stress," "prey" and "mating" signals back to spiders to see if it's possible to influence how they behave and construct webs.
"We're basically trying to communicate with the spider, listen to it and feed a signal back that is synthetically generated," he said. "I could hit a key on my keyboard and generate a fly-in-trap signal on the web and see if it comes running to me. That's what we're trying to do now. [We're] trying to speak their language."
The research, presented April 12 during the spring meeting of the American Chemical Society, was completed by Markus Buehler, Isabelle Su, Ian Hattwick, Christine Southworth and Evan Ziporyn, Massachusetts Institute of Technology; and Ally Bisshop, Tomás Saraceno and Roland Mühlethaler, Tomás Saraceno Studio, Berlin, Germany.