Angelina Jolie spent "months" preparing to sing in 'Maria'

Angelina, 49, said at the Telluride Film Festival: "I had seven months of opera classes, great teachers and Italian classes, and a supportive team that were going to help me."

Despite this, Angelina still felt anxious about singing when the time came to do it.

She said: "I was so nervous that morning I was out of my mind."

Angelina also revealed that she relished the experience of working with director Pablo Larrain.

She said: "I knew that as long as I gave my best, Pablo would be okay with it and somehow make it work. I knew I needed to do my best to try to help solve the puzzle, but I knew that he was a kind person and he was supportive and that helped."

Recently, Angelina actually revealed that she stopped singing after an ex criticised her voice.

The Hollywood star - who was previously married to Johnny Lee Miller, Billy Bob Thornton and Brad Pitt - admitted that she had to overcome her fears in order to play Maria Callas.

Angelina told The Hollywood Reporter: "It was an out-of-body experience because I don't sing.

"I had somebody in my life who was not kind to me about singing. It was a relationship I was in. And so I just assumed I couldn't really sing.

"I'd been to theatre school, so it was weird that it even had an effect on me. I just kind of adapted to this person's opinion. So it took me getting past a lot of things to start singing."