Angelina Jolie says starring in 'Maria' was a "gift as an artist" because she had to do "something that terrified" her.

The 49-year-old actress portrays Greek-American opera singer Maria Callas in the biopic and she trained to sing opera live on set to accurately portray the influential performer.

Jolie felt privileged to be pushed to learn a new skill as an actress as she approaches 50 and she wants to do more things that scare her.

In an interview with Times Radio, she said: "I think you're an artist, and you go through different things in life, and you wonder if certain parts of you have shut down, or who you are, what you have inside of you, and if your lights dimmed, and if you have less to contribute, or if you don't know your yourself, and so to push and rediscover things and try for things that I hadn't ever tried.

"And what a gift as an artist, to be pushed again at this time in my life, to do something that terrified me and I wasn't sure I could do is the greatest gift."

The final edit of 'Maria' features performances that are a mix of Angelina's voice and archival recordings of Maria.

The movie shows Callas - who passed away in September 1977 aged 53 - suffering a backlash from her own fans and Jolie could relate to Maria in terms of wanting to produce movies that people like and want to see.

When asked if she could relate to what Maria experienced, the 'Tomb Raider' star answered: "Not in that way, but I did relate to .. I do care about my work, and I do care about the audience. I don't make art for myself and so I do want desperately to connect.

"I want I see it as a relationship with an audience and I think it means as much to me as it meant to her. That it was probably a big part of our life, to feel less alone when our work connected to a stranger in the dark. You know, so for that, I think, and I'm sure she had her feelings hurt when somebody thought something about her that wasn't true.

"It's true, the public gave her a really hard time. I mean, I didn't, I think, you know, I hope the film expressed that she was dealing with a lot of private things. I think like we like we try to put forward in the film, she had serious health issues, and I think she wasn't able to express them as much as we could have today to say, well, she's not feeling well, and she's sick, or this is something she's or that she couldn't see on stage and needed those glasses she couldn't really see.

"So I think there was a lot about her that wasn't understood, and so she was unfairly judged sometimes as being like not showing up for something, or being a diva, when in fact, the effort to do what she did was harder than I think people knew. So I felt for her."