Dakota Johnson Enjoys a Night of Music at 2014 Petty Fest—Find Out Why She Didn't Perform

Fifty Shades of Grey starlet was photographed with her pal Ruby Stewart

Dakota Johnson is out of the Red Room of Pain and back in Los Angeles.

The Fifty Shades of Grey starlet enjoyed a night of music at the 2014 Petty Fest at the El Rey Theater on Thursday evening.

The 24-year-old, clad in tan leather jacket and black skinny jeans, flashed a smile as she made her way inside the event with model pal Ruby Stewart.

A source tells E! News that the brunette beauty hung out backstage all night, but did not perform at the Jameson-sponsored event, which gives 100 percent of ticket-sale proceeds to Sweet Relief.

"Her schedule got in the way of rehearsals for the show, so she decided just to hang out," the source explained. "She's a huge supporter of the fest."

The night of music honoring Tom Petty also featured musical acts by Flea, James Valentine of Maroon 5, Albert Hammond Jr., Danny Masterson, The Walking Papers, Brendan Benson, Nikki Lane and many more.

As for her role in Fifty Shades, some very lucky fans were recently treated to a five-minute preview of the highly anticipated erotic flick at CinemaCon in Las Vegas.

The overall consensus? The movie—which is based on the S&M thriller of the same name and stars Jamie Dornan as domineering billionaire Christian Grey and Johnson as innocent Anastasia Steele—is far more focused on romance than raunchiness.

The film is set to hit theaters on Feb. 13, 2015.