Sia

An Australian songbird with an angelic voice, Sia shows how much fun musical schizophrenia can be — the sweet-voiced damsel from Down Under started out as an acid-jazz siren, but wasted little time in branching out. TV viewers know her fragile, feathery crooning on "Breathe Me" as the sonic setting for the Six Feet Under series finale's tear-jerking climax, and her ethereal version of the Church's "Under the Milky Way" as the sleek soundtrack to Lincoln's sexy spot for their MKT town car. But her hits "Clap Your Hands" and "You've Changed" show the hip-shaking, club-ready, dance-diva side of Sia's talents, as she wails over funky, disco-flavored beats. And when she takes the microphone with chill-out pop sensation Zero 7, she steps into still another role, summoning a sensual, silk-sheets-and-candlelight vibe on the sultry, slow-burning "Destiny."

Sia roams through Britpop's past and present, in Next Steps.

As her cover of the Church's '80s college-rock hit showed, Sia has a knack for making other artists' classic tunes her own. The Kinks rarity "I Go to Sleep" has been covered by everyone from Peggy Lee to the Pretenders, but Sia's hazy, lullaby-like take on the tune takes you into a dream world of her own making. Radiohead never sounded so warm and cozy as when Sia swoops into her hushed, heavenly setting of their Britpop-goes-prog-rock anthem "Paranoid Android." But other artists have taken Sia's own songs into unexpected territory, too — Bristol breakbeat king Roni Size's remix of "Where I Belong" transforms the steady-grooving, acid-jazz-tinged tune into a skittering drum n' bass explosion.

When you've got a heaven-sent, honey-toned voice like Sia's — the kind that can melt the words of a tune into a crushed-velvet croon — the world will look to you for sweet, burnished ballads. Make no mistake, Sia's had her share of hits with those kind of songs, both on her own and with Zero 7, but there are other strings to her bow: She's just as comfortable belting out a disco-thumping, beat-pumping dance-floor burner, or pouring her powerful pipes into a big-production pop tune as she is cooing sweet, soft syllables into your ear. We've tagged all the most undeniable moments from every side of Sia's ever-shifting musical personality, from the hushed and heavenly to the furious and funky, offering you the ultimate tour of the unpredictable Aussie's world.