Florence Foster Jenkins was a socialite who threw parties in 1930s and 1940s New York and turned to singing, oblivious to the fact that she couldn't quite hit a note. "The first time I heard about the project," Streep says, "was when the director Stephen Frears called me and said, 'I have a part for you!' And so I said, 'What is it?' And he said, 'It's the worst opera singer in the world!" And I was thrilled."

Meryl Streep gives a wonderful performance in Florence Foster Jenkins

When she read the script she grew even more intrigued by the project. "Really the movie is much more than the story of the worst opera singer in the world," she says. "It's about a marriage, the happy, long relationship between two people whose self-interest was as equally served by the relationship as their honest feeling and affection for each other."

And when she looked into the real Florence, Streep was surprised by how easy it was to identify with her. "What's great about listening to her recordings, and what makes them heartbreakingly funny, is her aspiration," she says. "It's how much she wants it. You can feel her, you can hear when she takes a breath just a little bit too late to hit the note. But the aspiration is there, the desire, the love of music and how close she comes. That's what's so great."

Preparing to sing like Florence wasn't as easy as she expected. "I thought, 'Oh, this'll be a piece of cake because I can't really sing that well,'" Streep laughs. "But it was much more difficult. First of all, she tackled the most difficult arias in the canon of operatic diva performances. All these things that are very, very challenging coloratura - roles that are way, way up in the stratosphere. And just to sing as well as Florence Foster Jenkins was a challenge! So I started with a real, proper vocal coach, and he taught me these arias. And I tried to sing them as well as I possibly could at first. And then we went off into the landscape of, you know, mistakes!"

And Streep is sure that audiences will respond to Florence. "I think you'll like that she's a person who has retained something that we all have when we're children," she says. "When you're a kid, you can't really do anything that well. Nevertheless, you hurl yourself into the imagining of it. And you take delight in just the doing."

Watch the trailer for Florence Foster Jenkins: