Glen Hansard - star of the 2007 hit indie film “Once,” half of the he/she duo the Swell Season and leader of the Irish band the Frames - was watching a JFK documentary in his room at the infamous Chateau Marmont hotel in Los Angeles when he picked up the phone. A very rock star thing to be doing. Also very un-Hansard-like. But that’s part of the Swell Season’s charm. Two years of huge successes, including an Oscar for Best Song, and Hansard, 39, and musical partner Marketa Irglova, 21, still seem like the struggling buskers they played in “Once.”

Ahead of the Swell Season’s Friday show at Berklee Performance Center, Hansard clicked off the TV to talk about their stardom and a Cat Stevens tape he’s been jamming out to in his car.