We grade the current singles -- Britney's threesome, John Mayer's stoner reverie, Susan Boyle's Rolling Stones cover, and more fresh tunes

We grade the current singles

Britney Spears, ”3”
Non sequitur name-check of ’60s folkies Peter, Paul and Mary aside, there’s nothing remotely organic about La Brit’s panting, PG-13 ode to threesomes — a fembot-voiced, near-seizure-inducing dance-floor frenzy. C+

Kris Allen, ”Live Like We’re Dying”
The Arkansas Idol champ’s cover of an obscure B side from Irish pop-rockers the Script is a propulsive carpe diem anthem, part Tony Robbins, part mathlete (”We only got 86,400 seconds in a day/To turn it all around or throw it all away”). A-

John Mayer, ”Who Says”
Mayer channels Cat Stevens, Jason Mraz, and every camp counselor you ever had on this soft-rockin’ celebration of women, wild times, and getting stoned. B

Alicia Keys, ”Doesn’t Mean Anything”
Keys still knows how to craft an impeccable piano-soul ballad, even though her latest lacks the emotional wallop of similarly themed 2007 smash ”No One.” B

Carrie Underwood, ”Cowboy Casanova”
If Taylor Swift is country music’s prom princess, Underwood is her cool older sister, warning good girls about bad boys (”Looks like a cool drink of water/But he’s candy-coated misery”) over raucous guitars and a stomping ”whoa-oh” chorus. A-

Shakira, ”Did It Again”
R&B studio wizards the Neptunes deliver a spare, slinky backbeat for the Colombian yodeler with the truth-telling hips. Though not as camptastically loco as waning single ”She Wolf,” it still works up a nice little hiccupy synth groove. B

Susan Boyle, ”Wild Horses”
The Britain’s Got Talent sensation turns the Rolling Stones’ aching lament into a sort of church-lady serenade draped in piano and strings. No offense to SuBo, who imbues the song with genuine emotion, but it’s no match for the original. C

Death Cab for Cutie, ”Meet Me on the Equinox”
The indie demigods submit to Twilight madness, crafting a suitably moody piece of swirly-guitar atmospherica for New Moon‘s alt-heavy soundtrack. Hope they’re ready for a whole new fan(g) base. A-

Leona Lewis, ”Happy”
She may spend her entire career attempting to match the gargantuan success of ”Bleeding Love,” and this slow-build power ballad inevitably feels like a bit of a Xerox. Still, the Brit belter’s towering vocals could probably turn a grocery list into a top 10 hit. B

Justin Bieber, ”One Time”
The 15-year-old Usher protégé/tween pinup doesn’t release his debut until November, but he earns his pop-soul bona fides with this refreshingly age-appropriate chronicle of young love. B+

Foo Fighters, ”Wheels”
Is Tom Petty Dave Grohl’s spirit animal? The Foo frontman aims for old-school AM-radio gold on the band’s latest — all jangle, bombast, and big chorus. Cue the car-commercial tie-in in 5, 4, 3, 2… B-