Before her new film, Bel Canto, came along, Julianne Moore wasn’t exactly an opera fan. She’d attended precisely one, The Magic Flute, when she was 21. “And I left halfway through,” she said last week from her home in New York’s Greenwich Village, “to go make out with my boyfriend.” Peals of laughter ring down the phone.

You hear that a lot whenever you talk to Moore, 57. Her voice is full of mirth and mischief. She’s stealth-hilarious. She’s done more comedy than most people associate with her – she’s very funny in The Big Lebowski, I’m Not There and Maggie’s Plan. But she’s funny in those films because her characters take themselves so seriously. I wish someone would cast her in a pure, fizzy comedy, a Judy Holliday romp.

In Bel Canto, which is based on the bestselling novel by Ann Patchett, and directed by Paul Weitz (About a Boy, Mozart in the Jungle), Moore plays a more typical, serious role: Roxane Coss, a world-renowned American soprano who travels to an unnamed Central or South American country to give a well-paid private concert at a splendid mansion. Guerrillas storm the grounds, and a long siege begins. But over time, as captors and hostages get to know each other, the standoff softens into a strange and moving idyll of mutual understanding.

Moore has to sing in the film, several times. Well, she has to lip-synch – to the voice of Renée Fleming no less, arguably America’s most famous lyric soprano – which she knew could go horribly wrong. So she embarked on a crash course in opera.

With Fleming, Moore attended rehearsals for a benefit at Carnegie Hall, where she watched a stream of famous singers perform as Fleming pointed out the variety in their voices and tones. Later, when Fleming recorded the songs for the film, Moore sat five feet away so she could act out the sound breath by breath.

“I learned there’s a physicality to singing, not just the way you use your muscularity, but your physical self as an instrument,” Moore says. “When you watch opera singers close up, it looks like they’re singing in. The breathing and the sound they produce is kind of in the back of their throat and up to the top of their head. As actors, we’re taught to resonate in the facial mask. They do so much in the back of the head. It’s hard to describe, but it’s remarkable.”

On set, Moore wasn’t merely lip-synching; she was also producing sound. “I mean, I sound terrible,” she says, chortling, “but I’m warbling along, and I’m breathing along.” But there were takes where Fleming’s breaths were so long, Moore ran out of air. Fleming had to shorten some phrases so Moore could recreate them.

Fleming also told Moore juicy details of opera singers’ lives, some of which made it into the script. “Success means travelling all over the world, for three performances here, four there, and mostly being in a hotel room by yourself,” Moore says. “It can be miserable, especially for young singers. How easy it is to become isolated. So I wanted that idea in the movie, that Roxane didn’t understand how lonely she was, how she was craving community and relationships.”

As a young actress, Moore experienced that loneliness, too. So from the moment she had a family, they travelled with her to sets whenever possible. (Her husband is the director Bart Freundlich; they have a son in university and a daughter in high school.) That meant shooting in the summers, staying close to home and turning down a lot of work.

Oh, she keeps busy: Her film Gloria Bell premiered at TIFF this past September, and is due in March; she recently wrapped After the Wedding with Freundlich; and she’s now shooting The Woman in the Window, a Rear Window-esque thriller written by Tracy Letts and directed by Joe Wright. But Bel Canto was ideal for her, because the main location, the mansion, was located “just up the highway” in Yonkers, N.Y., with only a few days in Mexico City at the end to shoot the exteriors.

The fact that the film was an ensemble appealed to Moore, too. She gravitates toward them: Short Cuts, Boogie Nights, Magnolia, The Hours, Blindness and The Hunger Games franchise, to name a few. “I like something that represents a collective experience,” Moore says. “I like the multiple points of view. In commercial cinema, there’s often just one hero, and you’re supposed to identify with her, and it’s one point of view. That doesn’t always feel as human as I want it to. I want to put a finer point on things.

“And I like being with other actors,” she continues. “One thing I learned playing twins on As the World Turns, in the eighties – it’s really boring to act with yourself .” More peals of laughter.

In Bel Canto’s mansion location, there were no trailers for the actors – the international cast (which includes Ken Watanabe, Sebastian Koch and Christopher Lambert) lounged around the bedrooms, speaking in Japanese, German, French and Spanish as well as English. “Everyone was glad to stay together,” Moore says. “A bunch of characters forced into a situation, who end up building a community – I’m compelled by that, by language and communication, and how we communicate without language, too.”

The novel took 17 years to arrive on screen, but Moore finds the timing auspicious. “I think we have to move beyond nationalism and national identity, toward a cohesive understanding of who we are as human beings,” she says. “That’s what this film is about – people from different parts of the world, different socio-economic levels, different cultural barriers, coming to live as a community. It’s soothing to see something like this right now.”

The film also asks us to think about who we vilify, and why. When I mention that this feels especially significant at this moment, as the U.S. is whipped into panic about immigrant caravans, Moore sighs sadly. “It’s such a tumultuous time in the U.S. It’s hard to be pithy about it. But I’m heartened by the new activism I’m seeing.”

Moore is involved in the gun-reform organization Everytown for Gun Safety, and recently went to a fundraiser for Lucy McBath, who exemplifies that activism: After her 17-year-old son was shot and killed in a hate crime, McBath joined Mothers of the Movement, campaigned for Hillary Clinton and against relaxed gun legislation, and is now running for the U.S. Congress in Georgia’s 6th district.

“I met Lucy as an activist mom, and watched her candidacy grow,” Moore says. “To watch somebody be so galvanized, and do something so moving, who’s now translating that into public service – 10 years ago, I didn’t see a lot of that. But because of what is happening now in the U.S., the real lack of leadership, people want to step up. That I’m very heartened by.”

Read more here.