POP/ROCK

Ashley Tisdale, "Guilty Pleasure" (Warner Bros.)

Tisdale's debut, "Headstrong," was released in 2007, when several things were different. Her hair was blond, not brunette. She'd not yet had a nose job, a procedure that landed her under the tabloid microscope. And the country was still in the thick of the hailstorm that was "High School Musical," in which Tisdale had a starring role as Sharpay, whose goal was to derail the movie's star-crossed lovers.

Tisdale has said "Guilty Pleasure," her second album, was inspired by a failing relationship (representative song titles: "Erase and Rewind," "Delete You"), but that's really the least of her concerns here. This is album as image immolation, and Tisdale, now 24 but finally shaking the tween crowd loose, doesn't belabor the point, cutting to the quick in the opening couplet of "Acting Out," this album's first song: "Up above the surface I was just a perfect child/ But underneath it all I was craving to be wild."

So why does "Guilty Pleasure" sound so tame? It's full of the sort of high-test bad-girl pop not regularly heard since Max Martin first corrupted Britney Spears, as well as the brassy, guitar-driven shouters that have elevated Kelly Clarkson from "American Idol" winner to feminist pop star. "It's Alright, It's OK," produced by Alke and Twin, is brutally effective, a swinging kiss-off that Tisdale pulls off with verve. And "Tell Me Lies" has the zip of Disney-pop with a more troubling message.

But songs such as this no longer qualify as radical. Coming out as an adult is as unimaginative as remaining a child. Being bad, it turns out, is sort of boring.

JON CARAMANICA, New York Times

Mars Volta, "Octahedron" (Warner Bros.)

Vocalist Cedric Bixler-Zavala and guitarist Omar Rodriguez-Lopez wasted no time starting the Mars Volta after ending their speed garage band At the Drive-In. Since rocketing to Mars, they've made smug prog-metal with psychedelic touches of free jazz that was sharp and cold yet (if you disregard their oddball lyrics) easy to understand, no matter how complex their rhythmic shifts may have been. Yet, for all their dynamic range, they've never been warm or worried about melody until the quietude of "Octahedron."

With Red Hot Chili Peppers guitarist John Frusciante along for their most subdued and soulful effort, they find buoyant, hummable composition at their command on the heartbroken "Since We've Been Wrong" and "Teflon." These are, at their simplest, lovely melodies with weary lyrical embrace.

There's a curvaceous tenderness within this CD that has only been hinted at within Bixler-Zavala's laments or Rodriguez-Lopez's sonic leaps. Beyond passionate display, there's spaciousness -- something no crammed-and-cramped Volta album ever had. "With Twilight as My Guide" is space rock in the literal sense -- dreamy, open and crisp.

Still, for all the roominess and ruined romance that Mars Volta contemplates, there's hard steel ("Cotopaxi") found within "Octahedron's" dangerous curves.

A.D. AMOROSI, PHILADELPHIA INQUIRER