Seven billion humans may seem like a lot, but we're nothing compared with Earth's microbial population. Seabed sediments alone contain about 10 million trillion microbes for every person on the planet, and that's not even counting all the other microbes in places like soil, clouds and human intestines. Trying to study even a fraction of this biomass can produce a data overflow that's hard to comprehend.

Biologist Peter Larsen has faced this problem firsthand, drowning in data from his studies of microbial diversity in English Channel seawater. But rather than simply churning out more charts, Larsen and his team at Argonne National Laboratory recently had a better idea: They converted the microbial data to music.

"There are certain parameters like sunlight, temperature or the concentration of phosphorus in the water that give a kind of structure to the data and determine the microbial populations," he says in a press release. "This structure provides us with an intuitive way to use music to describe a wide range of natural phenomena."

It has become trendy lately to "sonify" scientific data, whether that means converting solar storms to scratchy dissonance or channeling gamma-ray bursts into a symphony for piano, cello and harp. A colleague suggested Larsen translate his algae data into classical music, but Larsen wanted to reveal the microbes' natural rhythms — and he worried the rigid patterns of classical music might get in the way.

"For something as structured as classical music, there's an insufficient amount of structure that you can infer without having to tweak the result to fit what you perceive it should sound like," he says. "We didn't want to do that."

Instead, Larsen sought the looser constraints of jazz. To do this, he assigned musical chords to environmental conditions like sunlight, temperature and nutrient levels, then matched microbe quantities under each condition to a musical scale. Thus, the chords play in different scales based on how the local environment affected the size of microbe populations. Here's one example, titled "Fifty Degrees North, Four Degrees West" in honor of the coordinates where he collected data:

The music above is based on a year's worth of data samples from five common microbial taxa: rickettsiales, rhodobacteriales, flavobacteriales, cyanobacteria and pseudomondales. Below is another composition, "Bloom," that focuses on microbes from relatively rare taxa such as opitulates, sphingomonadales and vibrionales:

"We were astounded by just how musical it sounded," Larsen says. "A large majority of attempts to convert linear data into sound succeed, but they really don't obey the dictates of music — meter, tempo, harmony. To see these things in natural phenomena and to describe them was a wonderful surprise."

For more examples of this technique, and to read about Larsen's methodology, check out his explainer page for "microbial bebop" at ANL.

[Via It's Okay to Be Smart, Tooth & Claw, ANL]

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