After a few pre-festival parties that got underway in Los Angeles earlier this week, the Sundance Film Festival has officially begun! Powerhouse singers Jennifer Hudson and Alicia Keys united in Park City, Utah at Hennessy VS's presentation of The Inevitable Defeat of Mister and Pete, a festival film starring Hudson as a struggling addict and co-executive produced by Keys. Meanwhile, the festival's founder, Robert Redford, posed with actor Joseph Gordon-Levitt at "An Artist At The Table," a roundtable discussion amongst independent filmmakers benefiting the Sundance Institute. Actor Phillip Friedman and The East star Brit Marling were also on-hand for the event. Click through the gallery to see all the stars at Sundance 2013!