KT Tunstall turned heads in 2004 with just the power of her voice and her guitar, but the intervening years have found her showing little interest in being just another worked-up folkie. On her third album, Tiger Suit, she leavens sleek pop songs with her warm-whiskey rasp, clawing against the digitized guitar in "Difficulty" and rocketing up the center of the galloping, tribal "Uummannaq Song." Though the album was recorded in the same Berlin studio where U2 created Achtung Baby, Suit's chief aim isn't experimentalism so much as empathy. "Push That Knot Away" may pivot on a pulsing dance beat and a tense, minor-key strum, but its lyrics are hellbent on encouragement: "May you always live in hope," Tunstall coos, as the storm builds behind her. That it can so nimbly navigate such contradictions is one of Tiger Suit's cleverest tricks.