Beyoncé and Jay-Z are throwing an Oscars afterparty at the Chateau Marmont in L.A. Sunday. The party is meant to be a celebration of singer Mary J. Blige's two nominations: for Best Supporting Actress in Mudbound and for her song from the movie, ?Mighty River.? The venue has reportedly been turned into a "very classy, old-school Hollywood glamor lounge" with a "huge crystal chandelier hanging from the center of the garage." The celeb power couple will host 150 guests at the bash." The Oscars air Sunday at 8pm Eastern time.