HBO’s Chernobyl exposed the horrifying story behind the 1986 nuclear disaster — and made a star of composer Hildur Guðnadóttir.
“We were in a room so vast that when you made a sound in there, you wouldn’t hear reverb,” says Sam Slater. “The sound just dissipated.” He’s talking about the Ignalina nuclear power plant in Lithuania, where he and Hildur Guðnadóttir went to record sounds and atmospheres for their Grammy‑winning score to the 2019 HBO/Sky mini‑series Chernobyl.
The successful duo likewise won Grammys for the score to the 2019 movie Joker, which also bagged Hildur an Oscar, a Golden Globe and a BAFTA. Hildur was born and grew up in Iceland, where she learned cello from an early age. She then studied and worked in Berlin, establishing a space in a studio built by a crew of experimental/scoring composers in the city’s Kreuzberg district. Sam is British, and studied Experimental Composition at Leeds University before moving to Berlin in 2013 to work with Jóhann Jóhannsson at the Kreuzberg studio. Appropriately, that’s where the two met. After all, they agree, studios are where most of the good collaborations start.
Hildur reckons there’s much to be gained from a close dialogue with your collaborator. “Specially big projects like the scores for films or TV series or computer games that we’ve been working on,” she says. “There’s so many different threads and angles and roads that have to lead in the same direction. There are so many places you have to look in the corners of. By their nature, these types of productions are huge collaborations between so many different departments. The sound and music is just one small part, because you also have the visuals, the costumes, the script, the cinematography. So to work in these kinds of projects, you really don’t have much choice — you just have to be able to collaborate.”
“We’re married, so we collaborate on life as a whole,” explains Sam. “But that wasn’t the case when we started collaborating together musically, and as we get better at that, I think sensitivity is the key word. It’s about understanding what the benefits of a collaboration can be — and whether it’s even needed.”
By way of example, he mentions some projects that Hildur’s working on currently. “And while I always love to be supportive if I can, in the current shape that they’re in, I’d just get in the way. In those cases it’s important to be sensitive to that and not let your ego dictate what to do. You have to know when to step back and recognise that the way to collaborate is actually not to participate this time.”
Their working collaboration began as a sort of composer‑producer relationship. “That was more to do with Hildur having all of these wonderful melodies and harmonies in her head, and me having a bunch of ideas to do with sound design, and how conceptual ideas for sound design can be used. We found some shared ground, specifically with Chernobyl, and then recently it’s been more of a composer‑composer relationship. But, you know, it’s a recipe for disaster if you insist on collaborating.”
In their collaborations, Sam handles the production and Hildur, as she puts it, has the space to sit and use her ears. They balance each other out, she explains. Not that Sam has neglected his own compositional work, which includes the score for the 2022 movie Guerrilla and his 2018 solo album Wrong Airport Ghost.
Hildur Guðnadóttir: "We wanted to go to the Ignalina power plant and capture its sound. We intended to use the building as an instrument."
For Chernobyl, says Hildur, “We had really strong ideas when we started the project that we wanted to go to the Ignalina power plant and capture its sound. We intended to use the building as an instrument.” Built along similar lines to the infamous Ukrainian plant where disaster struck in 1986, Ignalina is currently in the midst of a lengthy decommissioning process that began following permanent shutdowns of its reactors in 2004 and 2009. “We worked at Ignalina with Chris Watson, the field‑recording master,” Hildur recalls, “and we had a fantastic time with Chris. He’s a deep listener, which you don’t encounter that often. It’s a huge pleasure to go and listen to anything with him, really, let alone to record.”
She says they tried to capture the sound of the spaces at Ignalina without “activating” them too much. One particular star was an enormous door that provided some magical sonic gifts. “It had a whole symphony of sounds coming from it,” she says with a smile. “It had all these harmonics and things that were resonating wonderfully.”
Hildur, Sam and Chris had just six hours to complete their mission at the plant, much of which was taken up completing security clearances and putting on multi‑layered protective clothing. So the trio made sure they had open ears throughout their time there, as Chris deployed his double‑Mid‑Sides Schoeps array and a selection of contact mics. “So, there we were in the reactor room, and I’d never been in a space so large,” Sam says. “You don’t really have much of an opportunity to influence that kind of space interestingly. You need to be receptive to what’s going on in the space.”
They moved next into Ignalina’s vast turbine hall. “It made the reactor hall seem tiny in comparison,” Sam continues. “It was so long and so large that there’s a crane to move things from one end to the other. And all the while there were several thousand decommissioning staff in this factory, so there was so much for us to explore. There were tones, there were noise sounds, there were little melodies hidden in overtones, there were percussive ideas, there were things that acted as impulse responses. There was so much sound available if you got yourselves out of the way and concentrated on finding the right things. Really, we were sound hunters.”
Once they got back home to their base in Berlin, they began to sort methodically through the riches they’d captured. “Sam and I went gold digging through the material,” Hildur reports. “We microscopically listened to all of these recordings, many times over, and dug out what we could mould into musical clay.”
It took a good deal of patience and time to sit with many of the sounds in order to understand how they might use them in a musical context. “We began to realise we had enough material to build the whole score on,” she says, “and that was really exciting. I’d be sitting there with headphones and I’d be thinking ‘OK, now we’re at the fifth hour, 46 minutes, 20 seconds in, and right! There it is!’ So we’d dig that little sound nugget out and manipulate it — and very often it would be so high that we needed to pitch it down to an audible range, stretch it out, and mould it.”
Hildur: “We microscopically listened to all of these recordings, many times over, and dug out what we could mould into musical clay.”
In this way they built up a huge bank of sounds from the material and started to use them to compose the music. “It took a lot of time and patience to put together,” Hildur adds. “The story of Chernobyl needed this kind of approach, this much attention, so that we could marry the real events that have influenced so many people that are still alive today and who remember it happening, or have lost loved ones, or were somehow affected. It was really important that this reality was engraved in the music, that the music wasn’t just there to dramatise the events, with a conventional string orchestra or something. We really felt it had to be factual music more than fictional music, so that you can really feel the radiation in the music.”
A TV production like Chernobyl is a big, complex affair. Hildur says an important consideration for the composer is to determine the point in the process at which you actually start working. “Often with TV productions, the composer comes in really, really late, and maybe has something like three weeks to score a whole series. Whereas Chernobyl took a year, and I much prefer to start very early and for the music to be a bigger part of the DNA of the whole production and the whole story. I just find that way of working more interesting and artistically fulfilling — but the downside, of course, is that this takes way longer. And you don’t get paid any extra!”
Their sound‑gathering trip to the Ignalina plant in Lithuania happened right before the crew started filming the Chernobyl series there, because of Ignalina’s physical similarity to the Ukraine station. So Hildur and Sam felt they were working more or less in parallel with the whole production.
“While they were getting the visuals together and beginning the edit, we were already starting to sketch ideas and see what sounds might work,” Hildur says, adding that the overall intention for the score from all sides was to not dramatise the events. No one wanted a traditional drama score. No pianos and pads, Sam says with a smile. “We wanted the events, as horrific as they are, to really be able to just stand, undramatised, on their own,” Hildur clarifies.
Nonetheless, there’s quite a distance between a score that doesn’t dramatise the events, and one that uses an actual nuclear reactor in order to create a strange sound‑design‑oriented score. “Yes,” Sam says, “it was very unusual for a production as large as Chernobyl to have that much faith in a composer. Bear in mind that at that point Hildur hadn’t won the awards she’s won subsequently, and the director, Johan Renck, was a first‑time director in the series context. He just had so much confidence and faith in these crazy ideas that we were coming out with, and I think without that faith it would have been very different.”
As they dug through the sounds they’d collected at Ignalina, they came upon their recording of the door, which they’d both earmarked as a dead cert for use. It’s a good example of something that started life as a field recording and then, through processing, became musical. Minus an edit here and there, it formed the percussive core of the track that opens the Chernobyl soundtrack album, appropriately titled ‘The Door’. It might sound as if there’s a keen drummer playing perhaps with some brushes on a tin can. In fact, it started life as a drone sound, captured with contact mics on that Ignalina door.
“There was lots of tonal information in the mids,” Sam says, “but then up around 16k there was this tiny and incredibly fast fluttering that came from... something. But there it was. So, we’re in the studio and we go to isolate this fluttery sound. We were using a lot of old tape machines, basically to slow down this sound and move 16k to 8k to 4k and down into a usable domain. And the tape maintains enough structural integrity in the sound. I often find the same process digitally gives you something very brittle, but every time you slow something down with a tape machine, it’s adding noise on top, and if you then subsequently process that, the noise becomes part of the sound.” He used transient shapers and similar tools to accentuate the dynamics. “We ended up with this very broad, very beautiful‑sounding thing that’s chugging away in a very rhythmic pattern. It was an awesome groove!”
Sam contrasts this approach with what he calls the synth fetishism prevalent in Berlin, where someone might turn up their nose at your TB‑303, say, because, “‘Oh, that’s like the second generation version with the crappy filters, whereas I’ve got the real 303.’ A 303 or a drummer playing the same thing as that groove on ‘The Door’ doesn’t give the same effect, somehow.”
Hildur agrees: “The process you use to get the result you want when you’re writing music or recording music is as important as the end result itself. Because the way you were feeling or what you’re experiencing through that process is hugely influential on what the final result will be. That’s something I find very important — enjoying the process as much as you enjoy the outcome.”