Carey Mulligan on 'The Ballad of Wallis Island': 'Songs Are So Wonderful'

Carey Mulligan knew she wanted to be part of The Ballad of Wallis Island from the moment she read the script. "I just loved it and thought it was so moving, funny, beautiful—it made me cry," she told Newsweek. "It's really rare to read unbelievable writing, and I don't know if there's many films that really do that. So I wanted to be part of this group putting something lovely into the world that's just gorgeous."

Written by Tom Basden and Tim Key, The Ballad of Wallis Island expands on their 2007 short film The One and Only Herb McGwyer Plays Wallis Island. It centers on folk musician turned pop artist Herb McGwyer (Basden), who is booked to perform on a remote island only to find that the millionaire (Key) who hired him is pulling a bit of a "parent trap," having also arranged for his former bandmate and ex-girlfriend Nell Mortimer (Mulligan) to play the concert.

The reunion is meant to bring back the magic of their McGwyer Mortimer duo—but it also opens old wounds. What's more, Nell is accompanied by husband Michael (Akemnji Ndifornyen), forcing Herb to confront not only his past, but her present. In an exclusive conversation with Newsweek, Basden shared how the film evolved over two decades and the pandemic gave him and Key time to turn their long-gestating idea into a feature-length project.

Basden and Key's creative partnership began in the early 2000s as part of a four-man sketch group. Their early short films were made on shoestring budgets, relying on humor and inventive storytelling.

"We were just making these things out of the back of someone's car," Basden said. "We'd get food from a petrol station and shoot with whatever we had. But we loved the whole experience of making those shorts."

Their 2007 short film about a musician playing for a reclusive lottery winner on an isolated island gained a cult following and, over the years, the duo toyed with the idea of revisiting it. It wasn't until the COVID-19 pandemic halted other projects that they had time to expand the story.

"With scriptwriting, it's easy to get caught up in the things you're asked to do rather than the things you're most passionate about," Basden said. "During the pandemic, everything was put on pause and suddenly we could prioritize this film."

Director James Griffiths, who also helmed the short, was eager to return to the project. Known for Episodes and A Million Little Things, he helped shape the expanded narrative, ensuring the humor remained intact while deepening the emotional core of the story.

One of the film's standout elements is its original music, composed by Basden. He wrote 25 songs to reflect the phases of Herb and Nell's relationship.

"Tom's done the most brilliant thing in writing these songs so that you can understand their history as a couple just by listening to them," Mulligan said. "You hear when they were in love and you hear when it's all falling apart."

Mulligan's real-life husband, Mumford & Sons frontman Marcus Mumford, played an unexpected role. "It's still quite funny recording the songs in Marcus' studio and him picking up a guitar, like, 'Why don't you do a bit of this on it?'" Basden said. "I'm like, 'Yeah, I'm not a musician like you are, Marcus, I can't really do that. I can do the stuff I've recorded, so let's keep it that kind of level.'"

Basden was initially intimidated by the idea of his demos being heard by a professional musician. "I had to send these rough recordings to Carey and Marcus, which was terrifying," he said. "I was just hoping Marcus wouldn't listen to them too critically. But they were both incredibly supportive."

"I thought they were just so brilliant," Mulligan said. "I just wanted to be in the film in any way and the singing was just part of it. I think Tom is such a good songwriter. Even outside of the film, the songs are so wonderful." She added: "[The film] speaks to the universality and power of music and how one artist and one song can take you back in time to a specific moment. It's about the best in people and how we can bring out the best in one another."

Mulligan and Basden had an easy working dynamic, often practicing songs in her makeup trailer. The film's humor, much of it rooted in the chemistry between Basden and Key, made for a lighthearted set. "There's a great scene where Tom storms out and throws his dinner in the bin," Mulligan recalled, laughing. "Tim had a great time making gags about apple crumble—I was in pieces laughing but it's not in the final movie. I think there's a language barrier with Americans and crumble, which is a huge shame.... That was really fun to shoot."

Griffiths' relaxed environment allowed for improvisation and organic performances. "The set was a lovely place to be," Mulligan said. "Any time I got to watch Tim and Tom riff and their dynamics, that was my favorite. I got a front-row seat of all of their riffing. I knew I was going to be the straight man watching the guys be hilarious."

Yet the movie's emotional depth makes it resonate. "I think music, it does transport you," Basden said. "For Herb, he's slightly scared that all of the emotions that went into writing those songs will resurface when he plays them again, particularly with Nell. For Nell, the music is just an artifact—something she's moved on from."

"Nell isn't harkening back to another time," Mulligan said. "She would have been quite happy writing poetry and making jam. I see it as an adventure for her, but she's moved on that she can be an artist in other ways."

For lottery winner Charles (Key), McGwyer Mortimer's music played an important role in his marriage to his late wife—and he plays a key role in helping Herb face reality. "I think it's interesting that what sort of almost seems to be a romance between Herb and Nell becomes a romance between Herb and Charles as the film goes on," Basden said. "I think it's really important for the film that Herb doesn't get what he wants. The things he wants—money, relevance, reliving old glories—are things no one should want. He has to grow up and move on."

A full soundtrack featuring Basden's songs—also as a "greatest hits" for the fictional duo—will debut alongside the movie. "I am so excited to hear it when it releases," Mulligan said. "I am very much in backing vocals territory, so it's really quite fun to be involved."

"It's a bit of a cliché—the actor-writer who secretly wants to be a musician," Basden joked. "But I'll have to wear that label proudly."