"I AM ... SASHA FIERCE" BY BEYONCÉ; COLUMBIA

On Beyoncé's new album, the 27-year-old singer-diva-icon gives her on-stage, bump-n-grind alter-ego Sasha Fierce co-billing.

"I Am ... Sasha Fierce" is her attempt at a concept album, with the disc split into two.

There's the swoony, ballad heavy "I Am ...," which Beyoncé says reveals her true self "underneath all the exciting star drama." Then there's the more modern, hip-hop-influenced "Sasha Fierce," which Beyoncé calls "more sensual, more aggressive."

Does the split-personality attempt work? As a total package, not quite. Individual songs such as the role-reversal jam "If I Were A Boy" and saucy "Video Phone" shine, while other tunes don't produce enough oomph.

"I Am ..." starts off promisingly, with "If I Were A Boy" building on a soft rock acoustic guitar riff and handclaps.

"If I were a boy, I think I could understand, how it feels to love a girl, swear I'd be a better man," Beyoncé emotes. Written by BC Jean and Fergie collaborator Toby Gad, the tune — the only one Beyoncé didn't have a hand in writing — is one of the strongest she has ever done.

Then things start getting generic.

Slow burner "Halo" could be a love letter to her new hubby, Jay-Z, but it has such a conventional feel.

Thankfully, when "Sasha Fierce" begins with "Single Ladies (Put a Ring on It)," the album comes back to life with the hip-moving sassiness that Beyoncé delivers so well.

"Video Phone," a dirty ditty dotted with electro bleeps and groans, is guilty good.

Check out this track: Extra tune "Ego" is worthy of Beyoncé's role as Etta James in the upcoming film "Cadillac Records."