Here's the short version.
In 1859, the Sun belched out a huge ball of plasma. This plasma hit Earth, causing the strongest solar storm in recorded history - known as the Carrington Event after one of the many astronomers that monitored its progress in magnetic observatories around the world. As auroras danced across the skies as far south as the Caribbean, these scientists dutifully logged its peaks onto graph paper.
In 2012, a Carrington-sized storm narrowly missed the Earth, and by this point scientists had learnt enough about solar storms that they were very, very, very glad it did. To try to learn more, physicist Karen Aplin and meteorologist Giles Harrison painstakingly digitised the yellowing records of the Carrington Event from Flagstaff Observatory in Melbourne and published their findings in 2014, offering the data up to anyone who wants it.
In 2024, musicians Duncan Geere and Ben Dexter Cooley decided they wanted to experiment with live performances that use a process called "sonification" to turn data into sound. Both had experimented with sonification in the past, but wanted to find new, more expressive ways of rendering data through music. They decided to team up, collaborating on the creation of a data-driven score from the data published by Aplin and Harrison, but then interpreting that score in their own musical styles.
On this page, you'll find more background on The Carrington Event, details from Duncan and Ben about how they interpreted the data, and photos and recordings of their live performances. We hope that you're inspired by this work to make some sonifications of your own. If that sounds fun, check out the Decibels sonification community.
Here’s the long version.
Duncan: I've been talking about putting together a live sonification show for a while, and 2024 was finally the year that I put my time and money where my mouth is. A tonne of my brainspace over the first half of the year went into developing a live performance centred around the Carrington Event.
For the uninitiated, a solar storm is what happens when the Sun hurls a chunk of plasma and magnetic flux into space, and that chunk hits our planet. These "coronal mass ejections" or CMEs, as they're called, happen all the time (up to three times a day, during the Sun's most active phases) and normally they just whizz out into the vast emptiness of space. But occasionally Earth gets in the way, and that's when a solar storm occurs.
Luckily, all the iron in the core of our planet gives it a magnetic field. That magnetic field deflects most of the cosmic radiation (including CMEs) that is constantly bombarding us. If it didn't, the surface of our planet would be uninhabitable. This, incidentally, is pretty much why colonising the Moon is not a good idea. The deflection process is also the cause of the aurora borealis, and the aurora australis. It's space weather. And, incidentally, I highly recommend subscribing to spaceweather.com's newsletter for a regular dispatch of what's going on in the magnetosphere of our planet.
In 1859, something pretty spectacular went on in the magnetosphere of our planet - the strongest solar storm in recorded history, known today as the Carrington Event. It gets its name from Richard Carrington, an amateur astronomer, who observed and recorded a solar flare around the start of September. About 17 hours after he spotted that flare, the Earth was hit by an enormous chunk of Sun. There was not a whole lot of electrical infrastructure back then, but the operators of telegraph equipment reported getting electric shocks, and having sparks pouring out of their machines and igniting fires. During the peaks of the storm, telegraph operators reported being able to use their equipment without them being plugged into power or connected to batteries.
Auroras were reported as far south as the Caribbean, and in the Rocky Mountains the sky was so bright that it woke gold miners who thought it was morning and started making breakfast. In Australia, one miner wrote in a letter:
"Lights of every imaginable color were issuing from the southern heavens, one color fading away only to give place to another if possible more beautiful than the last, the streams mounting to the zenith, but always becoming a rich purple when reaching there, and always curling round, leaving a clear strip of sky, which may be described as four fingers held at arm's length. The superstitious and the fanatical had dire forebodings, and thought it a foreshadowing of Armageddon and final dissolution."
Armageddon did not happen. The storm peaked twice, and then faded away, and everyone went on with their lives. But if a storm of the same power hit the Earth today, things would be different. In fact, it almost did - in 2012, a "Carrington-class" CME erupted from the Sun and hurtled through Earth's orbit. Luckily, our planet wasn't there - it had passed by just a week beforehand.
If it had been there, the extent of our dependence on modern electrical infrastructure would have meant total catastrophe. A considerably smaller event on March 13, 1989, led to the collapse of Canada’s Hydro-Quebec power grid and the loss of electricity to six million people. A 2013 study from Lloyds insurers estimated that the economic cost to the United States of a Carrington-class event today would have been between US$600 billion and $2.6 trillion. Chinese researchers estimated the recovery time from such a disaster would be four to ten years. "In my view the July 2012 storm was in all respects at least as strong as the 1859 Carrington event," Nasa researcher Daniel Baker wrote in 2014. "The only difference is, it missed."
You might think there wouldn't be much data being collected in 1859, but you'd be wrong - quite a few observatories happened to be collecting measurements of the Earth's magnetic field at the time. In a 2014 paper, physicist Karen Aplin and meteorologist Giles Harrison digitised the records of Flagstaff Observatory in Melbourne, and when I contacted them they were willing to share that data. Thanks Karen and Giles!
Ben: Duncan and I have been longtime internet-friends, connected through fiber optic cables and our shared love of information design. More specifically, we started swapping ideas a few years ago around data sonification (largely thanks to Duncan’s pioneering work around Decibels, a data sonification community). The idea of a collaboration sat dormant for some time, until Duncan proposed we explore something called the Carrington event.
My knowledge of astronomy and physics is novice at best. But when I started reading about the history of the Carrington event, I was quickly intrigued. Imagine, in the year 1859, seeing the entire sky light up with auroras, an eerie glow spreading to parts of the world that would have never seen such a thing. For the unfamiliar, it may have felt like god or spirits or the end of the world. I kept thinking about this raw experience of the event, without all the technology we have today to understand the science behind solar storm events.
Aside from the historical significance, I was surprised at how much data was gathered from this storm, despite happening over 150 years ago. The variable names (declination and horizontal force) were foreign to me, but with a little bit of astrophysics 101 Duncan helped me wrap my head around the implications of what this data represented. It was time to start sonifying.
Here’s a quick look at the two main data variables from Google Sheets. You can already tell the storm “peaks” where declination and horizontal force split in opposite directions. This is easy enough to see visually, but harder to capture the drama of it in sound. For this reason we decided to create a “storm” variable (not shown in chart) which was a slightly more subjective interpretation of the chronological playing out of the storm.
I wanted my piece to have a central focal point, a single reference that listeners could easily identify with, so I chose to map the declination variable to the melody of a synthesizer (ie higher notes correspond to higher declination values). But I also wanted to incorporate the other data in some way, so used the horizontal force to modulate the release time of each note and also the sub amount of the oscillator. The new “storm” variable also came in handy to automate the amount of shimmer reverb present on the lead synthesizer.
This paired nicely with the modulated release time: when the declination level was high, and the horizontal force very low, it results in a high pitched note with a very long release time, which cascades through the shimmer reverb (set to a high value in accordance with the “storm” variable). Alternatively, if the horizontal force level is high, the sub level of the oscillator jumps way up, creating a short, staccato bass note, which to my ears sounded menacing and threatening. You can see in the data above, this moment happens just before the first storm peak. I found the combination of these sonification variables to be the secret in unlocking more subtle changes and tones in the piece, which otherwise may have felt too monotonous if the only sonification was “high values = high notes”.
Duncan: I built my performance around guitar, modular synths, and a custom script that I wrote for the Monome Norns music computer. The Norns script processes the data, sending signals that control my Eurorack setup. The guitar also goes into the Eurorack, where it's processed by an effects chain controlled by the data. Additionally, we agreed on using a collection of early recordings (including one from 1860, just a year after the Carrington Event), some more modern recordings of shortwave radio, and I threw in some white noise too. Here's a signal chain diagram for what's going on in my piece. It's complex, but if you have some familiarity with modular synths you'll probably be able to follow it at least a little.
If that didn't mean much to you, then don't worry. Basically, at the start and end of the performance, and in the lull between the two storm peaks, the guitar comes through pretty cleanly, alongside the recordings of people chatting over the radio. But when the storm hits, the radio is eclipsed by a fuzz of noise and the guitar gets sent into a combination of delay and shimmer reverb that make it sound enormous. It hits like... well, hopefully like a massive chunk of Sun.
My inspiration for this piece was post-rock bands like Explosions in the Sky, Godspeed You! Black Emperor, Sigur Rós, Hope of the States, Mogwai, Yo La Tengo's noisier moments, and Mono. I've always loved how post-rock can go from beauty to terror in a few short moments, and that's exactly what I wanted to capture here.
Ben: Early on in the process, Duncan and I agreed on a collaborative process that allowed each of us to bring our own musical take on the piece. We started with the same source material (the dataset) and also used the same tool for sonification (Duncan’s custom script for the Monome Norns music computer). We also pulled from the same collection of early recordings as samples for things like radio noise, white noise, and static.
For the sonification bits, I was interested in exploring a sort of blended approach between literal sonification of the data and a more human-interpreted, subjective relaying of the information. Duncan and I had been experimenting with this technique for a while, but then Tom Armitage wrote a blog post naming it “dynamic scoring” and we loved it.
Since I knew that I would be performing the piece live, I wanted to keep the composition rooted in analog hardware. Given the time period, and the quality of some of the early recordings from the 1860s, I decided to lean into the static and hiss-like nature of these sounds. Recently I’ve also been interested in using cassette tape loops in my musical practice, so this approach seemed to work on multiple levels. In addition to the Norns, I used two different hardware synthesizers, a Tascam Porta 05 cassette machine with a tape loop, another cassette player, and a few reverb pedals. Here’s what my signal flow looked like in the end.
The challenging thing about performing this piece live is also the perennial problem of the electronic musician—I only have two hands. I had to make some decisions about the right moments to add more energy, or dial back a sample, or introduce a new melody, or crank up the shimmer reverb. I feel this introduced a human element to the sonification that otherwise would not have existed if I automated everything in a DAW (which for recording purposes, I did end up doing a bit).
For the sonic character of the piece, I was inspired by composers like Nils Frahm, Hans Zimmer, and Max Richter. Given the nature of space weather and solar storms, my mind also immediately went to one of my all time favorite movies (and soundtracks) Arrival. I wanted the music to capture this ethereal, otherworldly glow happening in space combined with the eerie and foreboding nature of a huge solar storm.
Duncan: The three live performances I did of my Carrington Event piece were my first solo musical performances ever. I've played on stage before in a band, and as a solo DJ, but never performed my own work on my own. They went okay! All three had their own problems - the first was too loud, the second was too quiet, the third had some sort of limiter in the system but out of my control, where loud sounds ended up quieter than the quiet sounds, inverting the intended dynamic. But in terms of how I was able to express the data on stage, I was really happy with how they went.
Then it was just time to produce a recording. To make this a proper Loud Numbers collaboration, I twisted my Loud Numbers collaborator Miriam's arm into producing it. She very kindly listened to all of my nonsense about how it should sound and then ignored some of it to create a version that sounds amazing and much better than I'd have been able to do on my own.
Ben: The live performance of Carrington was a lot of fun. I performed the piece in Burlington, VT at Spiral House, a local arts collective of which I am also a member. I’m fortunate enough to be friends with Nate Hicks (aka Silence_Castor) who is an absolute wizard with TouchDesigner. He was able to create a custom video projection that looked like a huge sun, with flares emerging in real-time by reacting to peaks from my audio signal.
We also recorded the performance in full. Overall I’m pretty happy with how it turned out, although I would have liked the dynamics to feel a bit more dramatic. This is something I focused on a lot when it came time to properly record the piece—in a long sonification piece, how do you keep people interested and engaged, while also highlighting the really important parts of the dataset?
I started my tracking process by recording in the various tape loops that I had running when I played live. Then I recorded in the Norns melody (the key “sonification” bit) while improvising chords on a Juno pad underneath. Once everything was tracked, I focused on the dynamics—I automated the shimmer reverb to reflect the changes in the strength of the storm. I was also able to more exactly target when I wanted certain tape loops or samples to fade in and out, according to the energy of the piece at any given time.
I opted to use a few different radio recordings of operators testing their signal across the Atlantic Ocean. Despite being from a time period later than the Carrington event, I found the cross talk of the operators to be strangely captivating, like after the peaks in the storm people were reaching out to each other and checking connections in a sort of “what the hell just happened?” kind of way.
Duncan: Finally we sent off both recordings to the wonderful folks at Sorting Room Studios for mastering, who did a fantastic job of making it sound great on anything from a mobile phone to a car stereo to an enormous soundsystem.
While I didn’t have visuals during my performance, I wanted to have some sort of video to accompany the release so I partnered up with amazing multimedia artist Simon David Rydén to create a weird, ominous blend of visualization and flow fields. Our audiovisual version of The Carrington Event moves between views of the surface of the Sun, the Earth’s magnetic field, and a ground-level view of electrical infrastructure - represented by the Stockholm Telephone Tower. Huge additional thanks go to Ben Oldenburg for creating the 3D model of the tower. The music and video were exhibited at Malmö Gallerihelg, on the weekend of 28 September 2024.
OK. You've probably read enough now and just want to hear the thing. So here's the music. We hope you enjoy it, and if you have any questions at all, reach out to Ben and Duncan over email.