Selena Gomez gives impromptu performance at Sundance

Selena Gomez gave a impromptu performance at the Sundance Film Festival on Monday (20Jan14), taking the stage at a late-night party to celebrate her new film Rudderless.

The singer/actress is in Park City, Utah to promote the indie drama co-starring Billy Crudup and William H. Macy, who also marks his directorial debut with the film.

In the movie, Crudup plays a father mourning the loss of his son, while Gomez serves as the son's girlfriend.

Monday's party featured a set of songs from the film performed by musicians Simon Steadman and Ben Kweller, and Crudup also took the stage to sing one of the tracks, while Gomez joined Steadman and Kweller for the final number.

She then thrilled fans with an off-the-cuff performance of her hit song Come and Get It.