You'll have to wait for their completed albums, but the artists below have already hit the ground running with these sneak previews.
Kanye West, ''Runaway''
Self-awareness, thy name is (surprise!) Kanye. The rapper's raw, excoriating ''toast for the douchebags'' among other choice NSFW epithets reveals the hurt and insecurity beneath his Taylorgate bluster, in a confessional made all the stronger by its plaintive keyboard line. A-
Willow Smith, ''Whip My Hair''
Will and Jada's 9-year-old progeny brings a surprising amount of baby-diva swagger to this saucy, hypnotic ponytail-tosser. B+
Rihanna, ''Only Girl (In the World)''
RiRi's driving, techno-flecked come-on proceeds directly to the dance floor, a near-180 from last year's downbeat Rated R. But its strobe-light wattage doesn't reach quite as far as it should. B-
Kings of Leon, ''Radioactive''
Tennessee-bred brothers Jared, Nathan, and Caleb Followill (with cousin Matthew) make like the sons of a preacher man they are on their spiraling, gospel-choir-assisted ode to Southern roots. B
Josh Groban, ''Hidden Away''
The pop-classical star, who usually sounds like he's singing every note from some cliff top where eagles soar, is a model of (relative) restraint on this Rick Rubin-produced, ''Bridge Over Troubled Water''-esque ballad. B