If Some People Have Real Problems, upon its 2008 release, felt like Sia's "pop move," its warmly personable brew of mellow coffee shop soul offering a more approachable contrast to the sober soundtrack-fodder chill-out with which she -- and in particular, her increasingly ubiquitous, jazzily innocuous voice -- had become near-synonymous, what can we make of We Are Born? With this, her fourth proper album, recorded for yet another new label (pop/hip-hop titan Jive), the Australian singer has made a massive pop leap: a sunshiny, highly caffeinated set of frothy dance tracks and feel-good lite-funk.

And it's a great look.

It's hard not to smile in agreement when she sings, in the tremendously hooky chorus to the irresistible, disco-fied first single (a revamped Lauren Flax collaboration): "You've changed..

for the better!" As Sia tells it, it's less that she's changed than that she's finally made the album she'd been itching to make for years, the catalysts including her increased distance from the evidently dictatorial market forces of downtempo and her recent romantic linkage with DJ JD Sampson (Le Tigre, MEN).

Unexpected though the shift may seem, it still feels like an entirely comfortable one, a liberating opportunity to revel in the natural exuberance she's always held in check.

It's a treat, then, but hardly a surprise, to hear how well Sia works her ever-expressive pipes in full-on club-diva mode, as on the aforementioned single and the equally delightful "The Fight." She displays impressive vocal versatility throughout, cooing and crowing like vintage Gwen Stefani on the awesomely ska-punky "Bring Night"; drawing on her reserve stock of quavering Winehouse-isms for the blue-eyed R&B of "Be Good to Me"; getting throaty on the decidedly emo piano ballad "I'm in Here," which recalls any number of tortured '90s alt-rock songstresses (ditto her extravagant take on Madonna's "Oh Father.") Much as her vocal flexibility lets Sia navigate a considerable array of pop styles with nary a hitch, her solid songwriting chops find her fully satisfying the conventions of each form she tackles, albeit rarely transcending them.

Meanwhile Greg Kurstin, by now a past master of breezy, contemporary, grown-up girl pop production, supplies a likable balance of gloss and glitter, with plenty of fun, playful touches (toy pianos, synthesized orchestra bells, kids voices.) While We Are Born occasionally lapses into the anodyne, overly tasteful pop-folk balladeering of Sia's past, overall it's a charmingly cheery, light-hearted romp looking nowhere but sweetly, sanguinely forward.