When she was a young child, a severe case of conjunctivitis left her nearly blind. She recovered her sight after her grandmother’s prostitutes pooled their money to send her on a pilgrimage honoring Saint Theresa.

Her life included being accused as an accessory to murder (she was acquitted), friendships with Charlie Chaplin and Marlene Dietrich, helping the French Resistance, having the love of her life (boxer Marcel Cerdan) die in a plane accident, a serious addiction to methadone and, oh yes, recording some of the most unforgettable songs of the last century. When she died in 1963, the streets of Paris were lined with fans. Charles Aznavour (a Piaf discovery) remarked that the last time traffic had stopped in Paris was at the end of World War II. NEWSWEEK’s Nicki Gostin spoke with the actress. Excerpts:

NEWSWEEK: Were you nervous about taking on such an iconic role? Marion Cotillard: I was not so nervous, just because when I heard about Piaf, I didn’t know many things about her and her life. When I started to discover who she was, I felt something quite close. The fact that she was an icon didn’t scare me.

I thought everyone in France knew all about Piaf. No, in her time she shared all her intimacies, but the new generation we don’t know so much. We know her songs, but I really didn’t know anything about her personal life.

How did you prepare for the role? The first thing I did was read books and gather all the information I could find about her life. I watched a lot of footage and listened to her songs. That is technical, and then there is another part, which is trying to understand who she was. And that’s a thing which is hard to explain. When you meld the technical and emotional parts, it can create something.

Don’t you think part of her enduring appeal is her tragic life? Yes, she was an extreme person. She had that unique voice but that personality. From the beginning she was a punk. She was such a character. An artist is maybe not always having a normal life.

I read that you had to stop admiring her in order to play her. When you admire someone, you put a distance between you and that person, and I really had to erase that distance because I had to be the closest I could. Also I had to abandon all judgment I had about her and then abandon the admiration. To just look at her as the human being she was.

You lip-synch her songs. Were you nervous about doing that? I was more than nervous. I was terrified because I saw a lot of movies with lip-synching and I can’t remember a good one. I watched them again in order to understand why it was not good. I understood that your whole body is involved in lip-synching. It’s not just miming perfectly. When I realized this I decided to ask for a vocal coach because I needed to understand Piaf’s technique. And then I worked on the songs for hours, days and nights because it’s very technical and you just have to do it again and again and again. It was the hardest thing for me on the movie.

Which do you prefer doing, French or American movies? It’s not a matter of nationality. What I like in this job is you can travel to many places, many imaginations. So I don’t have a preference.

One more thing. Is there a law in France that Gerard Depardieu has to be in every movie made there? [Laughs] Maybe, I’ll check with him.