Joker and Chernobyl composer Hildur Guðnadóttir: 'I'm treasure hunting'

You can see why Todd Phillips, the director of Joker, was drawn to Hildur Guðnadóttir’s music. Elegiac and ghostly, with a dark, yearning heart, the score by the 37-year-old Icelandic composer suits Phillips’s character study of a troubled, broken man perfectly.

By contrast, Guðnadóttir is chirpy and prone to giggling. We speak via Skype: she is at home in Berlin, sat next to an acoustic guitar. In her young son’s bedroom – “next to his Lego and comics” – is Guðnadóttir’s Emmy, which she won in September for HBO’s series Chernobyl. Her remarkable score was constructed almost entirely from her samples of a nuclear power plant. It has since been nominated for a Grammy; the Joker score has been nominated for a Golden Globe and is being talked about as a favourite for this year’s Oscar. She worked on the scores simultaneously, but the two couldn’t be more different.

The Joker screenplay hit her hard. “I’ve never been as struck as I was with this,” she says. “I just really felt strongly for Arthur.” Phillips had asked her to start composing purely from the script, months before the cameras started rolling. She sat with her cello for a while, finally landing on a note that felt right for Arthur. “It was almost like it punched me in the chest,” she says. “And then this physical reaction, this movement happened, because I had found his voice, found what he wanted to say.”

She recorded some music and sent it to Phillips, who listened to it while rewriting his screenplay. When shooting began, he played her pieces on the set. When filming a scene in which Arthur retreats to a bathroom after his first murder spree, Phillips and Joaquin Phoenix decided to scrap the beats they had planned and, stuck for inspiration, Phillips played the piece of music Guðnadóttir had written. Phoenix reacted to it, improvising some interpretive dance. He had been struggling to find a way to have Arthur began to transform into the Joker; this was it.

When Phillips sent footage to Guðnadóttir, she was amazed. “It was magical,” she says. “It was completely unreal to see the physical embodiment of that music. His hand gestures were the same types of movements that I felt when I wrote the music. It was one of the strongest collaborative moments I’ve ever experienced.”

If Guðnadóttir’s Joker score speaks to Arthur’s mental state, her Chernobyl score conveys radiation. Just before the series was filmed in August 2018, at the Ignalina nuclear power plant in Lithuania, she went to Chernobyl with her score producer. Slipping into hazmat suits, they recorded for hours to pick up the ambient noise. She wanted the power plant – and the radiation – “to be a voice in itself. I wanted to understand the feeling of what must have gone through people’s heads as they were trying to navigate through that disaster.” It was incredibly effective: the result is like a sort of creeping death. “I didn’t know what it was going to sound like,” she says. “It was like treasure hunting. You go in there with completely open ears and you just listen.”

Guðnadóttir has long eschewed orthodox approaches to music; although she trained at classical music schools, she rejects the “right” way of doing things. Her mother sold her car to pay for five-year-old Guðnadóttir’s first cello; at 15, she began working with Icelandic band Múm, and since then has played with the likes of Throbbing Gristle, Sunn O))) and the Knife. “There are just so many dos and don’ts in classical upbringing,” she says. “But when I started to play with bands, none of those rules applied, and I just felt such a sense of freedom. It really changed the way I saw music.”

She has been a fixture on the underground music scene for years, but her scoring work is bringing her to wider audiences. “And that’s great. As a musician, you’re always hoping to bring new experiences, new ways of hearing sound and music to people. Experiencing music should be completely outside any boxes. Because it is such a nonjudgmental, instinctual art form. It goes straight to your heart.”

Film and television work certainly helps to pay the rent, and more doors are opening for her, but it doesn’t sound like she will be throwing herself into scoring. Her success means she is able to take some time out, to commit only to work that excites her. “I’m not going to focus solely on films; I’d get really tired of that. I’m getting a lot of offers right now. But it’s important for me to have space, because the work affects me so much. I just follow the curiosity carrot.”