Elton John’s Producer Andrew Watt likens the music legend to Beethoven: “He’s incredibly intense and unpredictable.”

Watt worked as the producer on Elton John and Brandi Carlile’s joint album, Who Believes in Angels?, which debuted in April.

Andrew Watt opened up about his experience collaborating with Elton John.

The 35-year-old Grammy-winning producer worked with the “Tiny Dancer” legend on John’s joint album with Brandi Carlile, Who Believes in Angels?, which was released in April.

Watt compared the 78-year-old icon to “Mozart or Beethoven” during the creative process. “I’d say he’s more like Beethoven, and when he’s writing, he’s extremely volatile,” he told PEOPLE, noting John’s well-known temper over the years.

While every artist has their own approach to creating music, Watt explained that working with John required a particular strategy.

“My role was to read the room,” he said. “If you were in Elton’s line of sight while he was writing, it was like being in the lion’s den. I made sure to stay close enough to respond if he needed me, but mostly tried to stay out of his direct eye line.”

Watt highlighted that John has a unique songwriting method, honed over decades with his longtime collaborator Bernie Taupin.

“He takes a lyric, puts it on the piano, envisions a movie scene, and essentially scores that scene,” Watt explained. “As he composes, he sings the lyrics, fitting them into the chords and creating melodies based on the words and how they sound.”

According to Watt, John relies heavily on lyrics to bring the story to life.

Describing the process of making Who Believes in Angels? with Carlile, 44, Watt called it “truly magical.” He recalled that John was coming off his retirement tour, which left him “exhausted, doubting himself, very self-conscious and insecure at times,” but the team worked to lift his spirits.

“And when he finally got through it, he was so proud. It was an incredibly special time, one I’ll never forget,” Watt said, adding that every day felt like “capturing lightning in a bottle.”