Much has been made of the peacocking crop of next-gen pop stars who have risen to take Christina Aguilera's place in the four years since she released her last studio album, 2006's Back to Basics especially a certain pantsless, zeitgeist-lathering Lady. That may explain the glut of cool-girl collaborators (M.I.A., Le Tigre, Sia, Nicki Minaj) on Aguilera's latest, though in the end, the 29-year-old singer's biggest adversary isn't Billboard's late-aughts parade of Gagas, Katys, and Rihannas, but her own bad habits.
From the earliest Britney-versus-Xtina days, Aguilera's vocal supremacy has always been her multi-octave trump card. Alas, that natural gift is too often negated on Bionic by her penchant for stock step-class beats and an aggressive, exhausting hypersexuality. The Minaj-assisted come-on ''Woohoo'' (''All the boys think it's cake/When they taste my woohoo'') and self-explanatory ''Sex for Breakfast'' pant lewdly alongside finger-snappy '90s flashbacks like ''Glam,'' ''Prima Donna,'' and ''Vanity,'' which seem to have been conceived primarily for walk-offs on RuPaul's Drag Race.
There is some redemption in several sharp guest spots: M.I.A. delivers on the squiggly, hypnotic banger ''Elastic Love,'' while Australian chanteuse Sia, co-writing and providing backing vocals, turns Aguilera into a smoky, almost Fiona Apple-esque torch singer on the lovely sequential ballads ''All I Need,'' ''I Am,'' and ''You Lost Me.'' If only Aguilera herself didn't seem so lost in Bionic's hollow, manic detours. C