Selena Gomez walked off stage without finishing her set at the Jingle Ball concert in Los Angeles on Friday night (06Dec13) after suffering severe sound problems. The 21-year-old singer/actress became visibly frustrated during the show at the city's Staples Center when her microphone failed, and she tried to explain the troubles to the audience, yelling, "Sorry, the sound isn't working!" Gomez urged the venue's technical staff to resolve the problem, but she eventually quit the stage without finishing her set when the issues were not solved. She was not the only star to suffer sound troubles at the gig - Ariana Grande was left struggling when her microphone stopped working during her first song, but the singer was able to joke about the troubles when the sound was restored, telling the crowd, "At least now you know I'm not tracked (miming)." The gig also included sets from Macklemore & Ryan Lewis and Robin Thicke, who also both performed at the Grammy Awards nominations concert in the city on the same night, as well as Miley Cyrus, who performed her controversial 'twerking' dance routine with a performer dressed as Santa.