Angelina Jolie spent “months” preparing to sing in ‘Maria’. The Oscar-winning actress plays opera singer Maria Callas in the new biographical drama film, and Angelina has revealed the extent of her preparation for the role. 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 experi…