In the six years since her debut CD ...Baby One More Time set Billboard charts a-trembling, Britney Spears has pried open pop music's rusty cage and sprinkled her sex-kittenish fairy dust around like long-overdue disinfectant. She has also arguably done more for the neglected navel than Jennifer Lopez and Beyoncé have done for the derrière. But despite her well-earned reputation for boldness (to which releasing a greatest-hits package after just four discs can only add), Britney calls it quits at making claims about her vocal talent. And that works in her favor. Because while My Prerogative is an exciting and even at times superb record, its merits lie almost exclusively in each track's production. From the Abba-esque choruses of her earliest hits ("...Baby One More Time," "Crazy") to the twitching, pulsed-up grooves of 2001's "I'm a Slave 4 U" to the technified bleeps and swizzles of 2003's self-skewering "Outrageous," the pop princess proves she's been largely content to let her in-studio performances take a back seat to the rhythm. With beats as consistently good as the ones she's managed to recruit, though, it's hard to blame her. "Toxic" and "Me Against the Music" mash trance and hip-hop into the mix, and the three previously unreleased joints don't shrink from sliding headfirst into new sound, either. The Bobby Brown cover and title track stomps and bomps to a bared-teeth backdrop, and "Do Somethin'" creates such dancefloor urgency it should come with a siren. "I've Just Begun (Having My Fun)" treads two steps shy of crossing the Britney-bred boundary between sexy and raunchy, but fans will hope it's autobiographical anyway. For detractors the song--and the disc as a whole--should signal a long wait till the party's over. --Tammy La Gorce