If, by magic, American Idol actually conceived a competition between this generation's greatest professional female vocalists (not the semi-pro pop tarts the show usually offers), it's hard to imagine who'd top Chan Marshall. The Cat Power singer proved an inspired interpreter on 2000's The Covers Record, and again on her latest, Jukebox, which distills the dusty, rebellious spirit of the Highwaymen's "Silver Stallion," and feminizes Hank Williams' "Rambling Man" with a jazzy swing. For the longest time, Marshall was a studio creation; her live shows were frequently marred by a mix of stage fright, alcohol, and self-consciousness. Marshall experienced a breakdown early in 2006 after releasing the stupendous The Greatest, and spent a week in a psychiatric ward. She soon returned to the stage with a renewed spirit and professionalism, which she credited to her newfound sobriety and the backing musicians from the album. She's since formed another terrific band featuring drummer Jim White (Dirty Three) and guitarist Judah Bauer (Jon Spencer Blues Explosion) to back her on Jukebox and on tour.