The American singer-and-actress stars as angel Platinum Fro in festive musical movie Black Nativity.

When preparing for a role on the big screen, Mary enjoys the process of getting into character.

"I love transforming. I love to be able to become something else, and use something familiar to become that thing. Use my life, or my mother's life, just transform because for a minute you're not you, but at the same time you are you. So it's just another way of expressing myself, just like through my music, it's another way of getting things out," she told

"My passion for acting came a long time ago when I was a kid. My music teacher would put me in some of the plays in school. It just was in me for a very long time. I never went for it until now in my career, so it's definitely been in me for a long time."

Platinum Fro looks out for actor Jacob Latimore's character Langston. Mary could relate to the morals of her character and found the bold costume helped her portrayal.

"What I loved about the character is that she was dressed up and she was fun, and angelic, but at the same time a figure of helping people and guiding people, which is you know - the angel," she continued. "I mean the hair definitely transformed me. It made me into you know an angelic creature because I wouldn't normally be walking down the street with a halo of white hair like that. So yeah!"

The film also features fellow musicians Jennifer Hudson and Nas. Mary was thrilled to work with them and has nothing but praise for her co-stars.

"I mean I just admire [Jennifer's] strength, I admire her acting, I admire her as a person, and vocally of course she's just amazing." she gushed. "Nas is the prophet. He's always been the person with the message. He's just always been a great person. He's very into what he is doing. He has a lot of integrity and his life shows that."