In the four years between Back to Basics and her brand-spanking latest effort, Bionic, Christina Aguilera has not only time-traveled several decades, but also taken quite a stylistic detour, from vintage soul and jazz to neo-futuristic electro-pop. Now, we could interpret this move a few different ways, not the least of which has a whole lot to do with the emergence (and eventual world domination) of Lady Gaga (herself often compared to Aguilera) and Aguilera's desire to remain culturally and commercially viable after her maternity leave. In many ways, however, Christina's cyborging of herself is very much in keeping with her career trajectory. This is an artist who (not unlike another blonde pop diva she's often compared to) has made a career of creative quick-changes, strapping on new looks, sounds and artistic styles like they were hair extensions. Not all of them fit — heck, some of them come off as downright silly (Xtina, anyone?). But flop or perfect fit, all of Aguilera's personas share at least a few characteristics: they are fun to watch. They are hot (Xtina, anyone?). And honey, they can sing. Take a walk down memory lane with us as we review the many faces of Christina Aguilera.

Disney Princess, circa 1998
After getting her start in the Mickey Mouse Club, the young Aguilera seemed poised for Disney-style pop stardom: wholesome looks, a slightly schlocky sound and an inevitable tie to a cartoon princess.
The Look: Sort of suburban soccer mom (that hair! that blazer!) meets Long Island Lolita (that red lipstick!)
The Sound: Heavy on the ballads. Hours spent emulating Whitney Houston into her hairbrush very apparent.
The Iconic Song: "Reflection"

Pop Lolita, circa 1999
Remember that period in the late '90s when pop music was basically synonymous with "blonde girls with ties to Disney trying to shed their wholesome image and prove they are all growed up by singing inappropriately sexual songs that made little girls and their daddies drool (in very different ways)"? Well, Christina wanted no part of that. Her uncomfortably sexy pop song was all about not giving it up, remember? You guys, she just wanted you to rub her the right way. Like a backrub. Duh.
The Look: Jailbait (read: a whole lot of bare midriffs)
The Sound: Dirty dance-pop but with a beat slow and sensual enough to show off those big pipes, which were also too old for her.
The Iconic Song: Uh, you know.

Latin Pop-Tart, circa 2000
Way ahead of the curve on this one, Aguilera (who is half-Ecuadoran) released a Spanish-language version of her material, featuring translated versions and several new cuts, and paving the way for the likes of Beyonce and Nelly Furtado to similarly reach out to the Latin audience.
The Look: Pretty much the same as her jukebox jailbait look, but with darker lipstick and exposed roots.
The Sound: Dance-pop is dance-pop in any language, and the material from her debut actually translates quite well.
The Iconic Song: "Pero Me Acuerdo de Ti"

Street-Walking Soul Sister, circa 2001
Foreshadowing (or perhaps inspiring) the birth of Xtina (and maybe the neo-burlesque movement), Aguilera laced herself into a corset to join Pink, Mya and Lil' Kim for a sultry remake of Labelle's "Lady Marmalade."
The Look: Courtesan chic, circa 1892, 1974 and 2001.
The Sound: Depending on your perspective, the throaty "Hey, hey, heeeyyyy" either launched a thousand melismas or was the point of origin for so much subsequent over-singing. (Wait, actually those things aren't really different.)
The Iconic Song: "Lady Marmalade"

Xtina, circa 2002
Christina really committed to this one, acquiring a new name and a bunch of piercings to go with her new Stripped-down persona. She caught a lot of flack for the "dirrty" spelling shticks and for what generally seemed to be a colossal case of trying way too hard. But don't underestimate Xtina. In the first place, you know damn well those chaps were hot. In the second, Xtina is also the persona behind "Beautiful," soundtrack for many a fabulous drag queen performance since and a mighty fine ballad in and of itself.
The Look: Dreadlock-esque extensions, enough dark eye makeup to make a serious dent in the (test) bunny population and all those piercings. Oh, and we mentioned the chaps, right?
The Sound: Hip-hop-infused dance pop that was a surprisingly good fit for Xtina's massive, hard-to-place voice.
The Iconic Song: "Dirrty"

Pinup Doll, circa 2006
The Mouse looms large over former Disney starlets' lives, necessitating not only a quarter-life crisis of identity/sexuality involving heavy-handed innuendo and copious amounts of exposed skin, but also the "No, seriously, take me seriously" response to/rehab from Crisis One. While Britney was busy breaking down and shaving her head, the former Xtina settled into life as a married lady and reinvented herself career-wise as a classic/classy cheesecake-meets-vintage-soul-loving siren.
The Look: Boogie Woogie Bugle Girl.
The Sound: She claimed Aretha and Etta as her major influences, but the singles were a bit more granddaughter of the Andrews Sisters. And, naturally, she still sang all of it like the second coming of Whitney.
The Iconic Song: "Ain't No Other Man"

Dancefloor Cyborg, circa now
Welcome back to the world of pop music you helped to create, Christina. A new regime has taken over since you left to have and raise your baby four years ago. You will be assimilated. Resistance is futile.
The Look: MILF-Machine
The Sound: Aguilera, Auto-Tuned?! Never thought we'd see the day. Four on the floor suits her, however.
The Iconic Song: "Not Myself Tonight." Uh, yeah.

Next up? Burlesque, a film about a girl from Nowheresville who heads out to the big city and makes it big on the neo-burlesque stage, starring our favorite Daughter of Reinvention. You can be sure she'll have a new look/sound/song/persona to match.