Justin Timberlake's sixth release from solo bow "FutureSex/LoveSounds" has earned props as the first time that six tracks from one release have hit the top 40 since Michael Jackson's "Dangerous" more than 15 years ago. With Beyoncé now stripped onto "Until the End of Time," it's quite likely JT will score the tenacious set's fourth No. 1—which has already catapulted into the top five at R&B. The meandering song is clearly a tribute to Prince, with its soul-soaked guitar-driven shuffle and funkified production—think "I Would Die 4 U" on Xanax. While Timberlake's vocals are smoothed out to near anonymity, as usual, he employs recognizable falsetto amid layers of appreciably creamy harmonies. It's Beyoncé, however, that really fuels the passion of the track, with her loosest vocal performance since "Listen" from "Dreamgirls"—and Timberlake is wise enough to sprawl her vocal across the song so that it commands the lead. The mantra here: unstoppable. —Chuck Taylor

While the turn of phrase may be cliché, the overall sound of "Unbreakable" screams it loud and clear: Backstreet's back. Unlike 2005's uneven "comeback" album "Never Gone," its follow-up finds the Boys dipping into their old bag of classic pop songs. They are a boy band with spot-on harmonies: They sing huge, hooky choruses; belt out sappy bridges ("I'm a house of cards in a hurricane," the group wails on "Helpless When She Smiles"); and bop and groove to slickly produced dance numbers. Nearly everything here is top 40 or AC radio-ready, particularly the piano-driven first single, "Inconsolable," and the Beatles-y "Unsuspecting Sunday Afternoon." The boy band heyday might be long over and the group is now a man down (Kevin Richardson departed to pursue other interests), but Backstreet's ready to try and melt your heart once again. —Jill Menze

There's an appropriate bleakness to Britney Spears' first album in four years, and her first as a tabloid figure rather than a vibrant teen idol. The hazy-eyed bump-and-grind of her "Gimme More" MTV Video Music Awards performance fits all this material: It's defiant like a bad drunk, uncomfortably oversexed and more at home in a seedy after-hours club than a celebrity ultra-lounge. The music ranges from shockingly minimal—"Piece of Me" and "Radar" have the synth fugues and smudgy bass of current underground electro and little else—to novelty pop, like the J.J. Fad-styling of "Freakshow" and Gwen Stefani-ripping snare march of "Toy Soldier." Spears is threatening or seducing, or both, on every track. This is still pop, but the last bits of Spears' song-and-dance girl veneer are cracking, along with the rest of her public persona. —Kerri Mason