CHICAGO TRIBUNE (BY GREG KOT) 3/4

Who says being a pop diva is easy? There is the constant pressure to look great and sound all-conquering while staving off a legion of younger sisters nipping at your stiletto heels. Which brings us to Mariah Carey, she of the 175 million worldwide record sales and the multitude of comebacks.

Carey's voice isn't what it used to be, and her last couple of records were lightweight even by her modest standards, brimming with adolescent lyrics and tarted-up production designed to keep her sounding fashionable. They restored her standing as a commercial force, but as an artist she sounded adrift.

On her 12th studio album, "Memoirs of an Imperfect Angel" (Island), Carey doesn't resort to vocal histrionics or production gimmickry. Instead, she plays it low-key, and ends up with her best album since the '90s heyday.

A few caveats: The first single, "Obsessed," isn't typical of the album as a whole, with its Eminem-baiting video, distorted wordless vocal hook and accusatory lyrics. Neither are the rap cadences Carey adopts for the combative "Up Out My Face."

Otherwise, Carey focuses on introspective ballads. Her voice has lost range off the top, but she's learned how to inhabit a song rather than simply knock it around like a rag doll with her rocket-propelled trills. Rather than farm out songs to a series of producers, she primarily sticks with the songwriting/production team of Tricky Stewart and the Dream, who frame her voice in subtle, low-key arrangements. Using sparse keyboards, a spritz of strings, a kick-drum rumble here and there, and lots of slow-motion handclaps and sensual finger snaps, they dial down the bombast considerably. In response, Carey turns in some of the most measured and beautifully understated singing of her career.

Her voice is frequently multi-tracked to create the illusion that she's dueting with herself, with counterpoint melody lines. The effect is nothing new in R&B; Marvin Gaye turned this studio technique into an art form on his 1971 masterpiece "What's Going On." But the old-school soul connection is appropriate: This is Carey building on slow-jam R&B and adult-themed ballads to create a loose song cycle about love lost and regained.

As the album title suggests, the melodrama can get thick at times, and a few of the songs are a bit slow in developing, revealing their hooks reluctantly. "Betcha Gon' Know" aptly sets the melancholy, inward-looking mood, but as an album-opener it's a bit of snooze. It's not until "Candy Bling," with its back-in-the-day reminiscences, that things pick up.

Carey really hits her stride on "It's a Wrap"; she sounds refreshingly raw, surrounded by the most minimal of instrumental backdrops. As she emotes with just a hint of grit, a small squadron of Carey voices loop in and around her lead vocal, giving the song just the right amount of decoration.

"Impossible" is almost impossibly fragile, but Carey turns it into a tour de force of soft-core texture, as if whispering into a lover's ear. "Angel (Prelude)" brings out the high-pitched vocal flights that were the singer's signature earlier in his career. But instead of showing off, she's going for something eerier with a muted, otherworldly tone.

A cover of Foreigner's "I Want to Know What Love Is" is an appropriate closer. After an album in which the distance between pillow talk and recrimination, seduction and betrayal is painfully thin, it's a potentially potent gospel plea. Unfortunately, it resorts to the soft-to-loud-to-louder formula that has ruined many a power ballad in this "American Idol" era. Perhaps this was Carey's opportunity to prove that she can still climb those Everest-like octaves. Fortunately, the restraint she brings to much of the rest proves she's maturing into more than just a vocal acrobat.