First comes a cacophony of gongs, then flutters of chimes, then a deep melodic whale call—these are the sounds of the first musical instrument powered by biotechnology. The music comes from a black box in the home lab of Josiah Zayner, a biophysicist at the University of Chicago. Inside the box blue lights pulse on vials of proteins, which in turn trigger the sounds. Zayner calls it the chromochord. “Chromo” refers to the colored lights and “chord” refers to the strings of a musical instrument. Essentially, it’s light activated. “Scientists see beauty in a well-crafted experiment,” Zayner says. “The chromochord allows other kinds of people to experience that beauty.”

The chromochord relies on proteins from plants that respond to sunlight, known as light-, oxygen- and voltage-sensing (LOV) proteins. Sunlight causes proteins in leaves and stems to expand, which sets off a cascade of cellular signals that allows plants to grow toward a light source. Zayner isolated LOV proteins from oats, collected them in vials and bioengineered each sample to react differently to blue light. “People don’t have the chance to consciously experience life on the cellular level,” says Zayner, who studies LOV protein activation and movement in his research. “This brings it smack-dab in their ears.”

The chromochord holds 12 vials, each paired with a different sound. When light shines on one vial the proteins inside swell, changing the wavelength they absorb. A sensor measures the change in absorption and cues the sounds. As one set of proteins slowly expands, the chromochord emits the deep thrum of a bass; as another setquickly shrinks, out comes the sound of glass chimes.

“There is something conceptually appealing about hearing the sounds of biological things,” says Jason Freeman, interim director of the Center for Music Technology at the Georgia Institute of Technology. “These proteins have their own music to them. People make music out of mold, nanoparticles or all kinds of things. There’s something intrinsically interesting about these projects because they’re seeking to make audible that which is normally inaudible to us, to reveal something that may be a little bit mysterious or invisible to us in nature.”

The first chromochord prototype had a push-button interface but Zayner found it unwieldy and finicky when he first played it at a physics conference in Berlin. Instead, he wanted to create a more portable and reliable device, so he partnered with composer Francisco Castillo Trigueros on a second version. The two met after Zayner sent a mass e-mail to composers at the local conservatory. “Francisco was the only one who responded,” Zayner says. Trigueros wrote the music and Zayner translated it into automated light pulses and built the machine.

The two make a surprising pair: Zayner has a lip piercing and a large cross tattoo on his chest, whereas Trigueros wears V-neck sweaters and collared shirts and is often mistaken for the scientist.

In May the collaborators had their first two-day musical installation at the University of Chicago. The room was dark and the sounds were eerily calming. On the front wall projections of deep-blue blobs morphed into one another, a visual representation of the sounds. But on the second day of the show the proteins began to stick together. The musical phrases turned into noise and the visuals faded. “The installation that we set up had beautiful music,” says Zayner, “but then over time the music would slowly be distorted as the proteins started to fail.”

The breakdown surprised Trigueros: “I had to rethink my role as a musician.” But it was Zayner’s intention. “In our bodies, there might be a million proteins in a cell. Some of them get damaged—things happen,” Zayner says. “In the end it’s not perfect, but it’s still beautiful almost because of that imperfection.”

Others seem to have agreed. “I think the audience was pretty enamored with it,” says Julie Marie Lemon, the program director and curator of the Arts|Science Initiative at the University of Chicago. “In a sense, the life of the protein was being experienced.”

Zayner and Trigueros next plan to create another musical instrument, this time using cells and sound, rather than light to stimulate them. They hope to expose bacterial and one day human cells to music and measure how the cells’ pressure-sensitive ion channels respond. When sound waves hit the channels, a surplus of ions floods through the cell and elicits a response that can be translated into new, different music. “This is just the seed, and we will see how the tree grows, but it could be really strange,” Trigueros says.