On her wildly hyped sophomore album Barricades & Brickwalls, Australian alt-country star Kasey Chambers establishes her artistic identity crisis—and genres-spanning appeal—not five minutes in. After proclaiming her tenacity on the title track with the aid of gritty twang and dirty electric guitars, she immediately plunges into "Not Pretty Enough," a self-pitying ballad that makes Gwen Stefani sound like the epitome of brash confidence. Clearly influenced by maverick singer-songwriter Lucinda Williams, who guests on the terrific "On A Bad Day," Chambers benefits from a promotional machine that views her as a pop-minded, publicity-friendly, midriff-baring variation on her fiercely persnickety mentor. Which is precisely what she is on Barricades & Brickwalls, an album gentle and rustic enough to appeal to O Brother, Where Art Thou? fans, while ceding a few tracks to poppy material that might draw nibbles from the adventurous fringes of the Nashville crowd. As such, Barricades frustrates in spots, but it's immensely ingratiating, with bonus points for appearances by Williams, Buddy Miller, and the Aussie pop-punk band The Living End, which juices up the appropriately rocking "Crossfire." Chambers only truly misfires on the bonus track, "Ignorance," a shrill screed that catalogs every societal ill short of unpaid library fines, then castigates its presumably complicit audience with the bumper-sticker slogan, "If you're not pissed off at the world, then you're just not payin' attention." But even that sour medicine is made easier to swallow by the 48 minutes of sugar that precede it.