On September 17, actor Julianne Moore stopped by Late Night With Seth Meyers to chat about her new movie Bel Canto (out September 14). The Oscar-winning actor stars as an opera singer in the adaptation of the famous book.

“Based on a true story, the 1996 hostage situation in Peru at the Japanese embassy,” Moore explained, though her character is a fictional addition. “It's a political thriller and a love story.”

Read: HOW JULIANNE MOORE LEARNED TO SING LIKE RENÉE FLEMING FOR HER LATEST MOVIE

Moore stars opposite actor Ken Watanabe, who earned a Tony nomination as the King of Siam in the 2016 revival of The King and I. He is currently reprising the role opposite his original leading lady, Kelli O’Hara, in London’s West End.

Moore brought her acting chops to set, but Tony nominee and Grammy winner Renée Fleming actually provides her singing voice for the film. “I can't sing,” said Moore, who did have to sing on set to create the illusion, but whose voice was replaced in post-production. “In order to do that you have to try to learn to sing. I studied with [Renée’s] coach and watched a lot of opera and went to the Met."

Still, Moore felt extremely self-conscious on set. “Everybody in the sound department can hear you because you're miked so they're the ones who are there holding the boom [wincing],” she said.

Bel Canto is currently playing in theatres.