Looking like she stepped back in time, Mariah Carey rocked old school curls and a simple LBD at the Precious pre gala cocktail party at the Royal Ontario Museum during 2009 Toronto International Film Festival last night (September 13).

Joined by co-stars Gabourey Sidibe, Paula Patton and Sherri Shepherd, the 39-year-old singer/actress was on hand to celebrate the much buzzed-about indie drama that Tyler Perry and Oprah exec-produced.

While on the red carpet, Mariah — who dramatically glammed down to play a social worker — said a climactic scene in which Precious’ mother (played by comedienne Monique) is confronted about the abuse the young girl suffered was so difficult, she and the other actors cried between takes.

“None of us were supposed to be crying, but it (the scene) was so deep and so raw, that we couldn’t help it, she said. “Cameramen were crying.”

Others at the Four Seasons Hotel to watch the film or catch a glimpse of Lady O: Mary J. Blige, Gayle King and Robert De Niro, whose wife Grace Hightower has a song in the movie.