After three albums, Austin's Sour Bridges has dialed in an effervescent blend of bluegrass and happy rock. The piano- and drum-infused string band's vocal harmonies are stunning, their compositions are crafty, and the amusing accounts of Southern living are penned with grace and clarity. Unfortunately, the geeky Americana styling they've dubbed "browngrass" remains friendly and eclectic in all the wrong ways. Townes Van Zandt famously asserted, "There's only two kinds of music: the blues and zippity doo-dah." Sour Bridges plays the latter to the extent that they can't even make a sad song sound sad. On downtrodden closer "Southeastern Corner," banjoist/guitarist Bill Pucci fails to drop an ounce of emotional weight on the vocal. Similarly, chromatic country gospel number "Dirt Poor" starts from the gut and ends with a Beach Boys-esque vocal that turns dangerously saccharine. Best tune "Meet You There," sung by bassist Jack Bridges, thrives on emotion with a telling line: "If your song's got no soul, put her back till she's done."