On their first two albums, the Canadian sibling duo Tegan & Sara were alterna-folkies who hit their acoustic guitars with the fierceness of closet rockers. On 2000’s This Business of Art (Vapor), they flirted with plugging in their guitars and growled as often as they cooed. Here they’ve finally kicked the closet door open, turned up their amps, and started to sound like a full-fledged rock band, replete with the overdriven guitars and muscular drumming that introduce them on the disc’s opening track, "Time Running."

Produced by John Collins and Dave Carswell of the New Pornographers, If It Was You mixes and matches toughened rockers with hook-filled pop numbers, both of which take advantage of the sisters’ rough-hewn harmonies. Tegan & Sara throw in a couple of left-field treats, including the bluegrass-tinged "Living Room" and the reggae-flavored "City Girl"; the results belong more up Sleater-Kinney’s edgy riot grrrl alley than in the quieter confines of listening-room folk. That formula isn’t likely to go over well with fans who were hoping to see Tegan & Sara grow into the next Indigo GirIs or join Ani DiFranco as folkies with attitude, but it’s likely to give the duo access to an entirely new audience.