How do you define success? Is it fame and fortune? Prestige and privilege? Recognition? Love?

Whichever one you pick, it would seem Diana Krall isn't hurting. She's got talent, looks, hit albums, a shelf of awards, and a new husband in none other than Elvis Costello. But with her eighth album The Girl in the Other Room, Krall gives the impression that for her, the true measure of success is artistic self-determination.

On this dozen-song effort, the acclaimed jazz singer-pianist grasps the reins of her career and her music more firmly than she ever has before: She co-wrote half these cuts with Costello. She co-produced the album with longtime collaborator Tommy LiPuma.

She has traded in her elegant torch-singer look for a softer, more earthy and casual image. And perhaps most significantly, she has moved away from the jazz standards that defined her early career in favour of rootsier, more contemporary material by the likes of Tom Waits, Joni Mitchell and Chris Smither.

If it sounds like Krall is attempting to morph into another Norah Jones, well, yes and no. Granted, with their piano-chanteuse backgrounds and recent shifts toward a more accessible pop sound, there's plenty of common ground between the two.

But Krall, despite her changes, remains more of a pure jazz artist than Jones. Whether she's revamping Waits' tangoish Temptation into a sultry seduction, swinging the blues on Smither's steamy Love Me Like a Man (as covered by Bonnie Raitt) or spreading her lyrical wings with Joni's poetic Black Crow, Krall sticks to the jazz-club approach that has served her well for more than a decade.

Indeed, if you didn't know a word of English, you couldn't spot the difference between the pop covers and jazzier fare like her smoky take on Mose Allison's Stop This World, her gorgeous reading of Costello's haunting Chet Baker homage Almost Blue and her poignant version of the Billie Holiday chestnut I'm Pulling Through.

The finest moments here, though, are also the most telling ones: Six collaborations between Krall and new hubby Elvis. Similar in mood to the sombre, romantic fare on Costello's latest disc North -- most of which was basically a love letter to Krall -- ballads like the bluesy I've Changed My Address, the soulful Narrow Daylight and the heartbreaking Departure Bay are so smartly crafted and emotionally powerful you'll wonder why she bothered playing cover tunes for all those years.

Sure, the jazz purists will scream sellout. And thanks to her new, more commercial stance, Diana will probably become an even bigger star than she already is. Never mind any of that. What really matters is that The Girl in the Other Room is the most personal, original and fully realized album of Krall's career.

And that makes it a success no matter how you define it.

Track Listing
1. Stop This World
2. The Girl In The Other Room
3. Temptation
4. Almost Blue
5. I've Changed My Address
6. Love Me Like A Man
7. I'm Pulling Through
8. Black Crow
9. Narrow Daylight
10. Abandoned Masquerade
11. I'm Coming Through
12. Departure Bay