After a four-year hiatus, Christina—or “Xtina”—is back with 18 tracks that find the artist straddling the line between Lady Gaga and Regina Spektor, with a smattering of the overindulgent schmaltz that has become synonymous with the majority of the post-Mickey Mouse Club cohort of female pop singers. Despite giving birth to a son, Max (whose pictures she unabashedly sold to People for a reported 1.5 million big ones), Christina shows no signs here that family life has made her any less prone to fits of flagrant sexual exhibitionism.

No doubt taking nods from Madonna and the like, Christina isn’t afraid to shake, thrust, and hustle, as she professes on “Glam”, an obvious homage to “Vogue” that isn’t nearly as catchy or sultry as it thinks it is. Awkwardly, the song is anchored by a preposterous and unworthy intro where Mrs. Aguilera informs us neophytes that “Fashion is a lifestyle / It’s a choice / It’s freedom of expression / You have to live it / You have to love it.” By the time she delves into the chorus, where she sings, “Don’t let the clothes wear you”, one can’t help but burst out giggling in embarrassment for her. Is Aguilera being ironic? Surely, the yummy mummies of the world can’t expect to be seen trailing their kids to school while dressed in leather cat suits and knee high boots, as Christina does so boldly in the music video for the first single, “Not Myself Tonight”.

But don’t let Aguilera’s foolhardy taste for adventurous fashion distract from some of the album’s musical merits. The opener “Bionic”, for instance, is a thumping electronic number co-written with UK DJ/music producer Switch and Kalenna Harper, one half of P. Diddy’s hip-hop group Dirty Money. Elsewhere, on the captivating Tricky Stewart number, “Prima Donna”, Aguilera is found doing her best Michael Jackson impersonation. If the album were limited to this retro mixture of shouty pop and robot glam, then perhaps this would have been a record worth writing home about.

The best number, though, is undoubtedly the closing piece “Vanity”, a disco banger that finds the singer professing just how much she loves herself. Without a modicum of humility, “Vanity” finds Christina crooning about the wonders of her own image and ends with Aguilera proclaiming to marry none other than herself. It’s an intelligent postmodern play on the tabloid pop star. At first, as Xtina starts telling us how she turns herself on and that “V is for vanity / Thank you mom and daddy / Yes I’m vain / So what / So what”, one can’t help but resist the smutty urge to fling one’s body on the floor like Xtina did back in the 2003 video for “Dirrty”. When that signature Aguilera wail finally kicks in at the end, the listener is unable to resist reveling in the overindulgence. It’s so good, in fact, that this listener would be happier if the whole album were merely 17 remixes of that very track.

Instead, we get stuck with Linda Perry downers like “Lift Me Up”, which is one of those shallow, vomit-inducing laments barely good enough to pass for a winning song on an American Idol finale; it’s certainly no better than a retro Aguilera B-side like “Too Beautiful for Words” or an A-side like “I Turn to You”. Alas, one is forced to wade through fragments like “I Am”, which finds the artist self-consciously rolling the letters off her tongue in an attempt to sound more like Regina Spektor or Fiona Apple than Mandy Moore. Unfortunately, the results come off a little insincere, if not downright silly.

In the end, it is Aguilera’s overzealous penchant for excess that leaves this comeback short of, well, being any good. Uncertain of which fan base she wants to aspire to, she finds herself masquerading through dual identities: the vulnerable Christina of Mulan’s “Reflection” one minute, the nymphomaniac of Stripped in the next. However, as the whispers in “Vanity” profess, Christina may very well have pleased her most important fan—herself.