Robustly talented but frustratingly lost, Christina Aguilera is a lesson in regression, a saucy teen prodigy who turned into a lights-out soul belter — who turned into a paranoid pop-drivel bore. You're better than Britney; think Adele, Xtina! But alas, the 31-year-old shouts to be heard these days, not realizing, or maybe ignoring, that we adore her when she cuts the clatter and the crass and simply uses Those Peerless Pipes.Aguilera's new album, the largely uninspired Lotus, is rife with "I'm tough" 'tude and rote production. I don't mind when she gets dirrrty. But I can't deal with the chip on her shoulder (about her weight, about her dating life, about her tepid sales, about her diva role on The Voice) and her insistence on burying her talent in been-there beats. "Aren't you tired of throwing stones?" she asks on Best of Me, with its military band drive, a tired fad for sure. "I don't care what the world thinks," she falsely boasts on the petulant Sing for Me. "One of me is wiser / One of me is stronger / One of me's a fighter," she shouts on Army of Me. Gosh, it's just ME, ME, ME with this one!Superstar producers Shellback and Max Martin don't do Aguilera any favors with yawny dance-floor sonics and lackluster production. First single Your Body, her supposed big comeback cut, is so milquetoast and startlingly generic in its artistry and synthetic grind, it floundered on the Billboard charts at a time when Rihanna and Nicki Minaj can pretty much sneeze on vinyl and make the Top 10.Oh, it's a mess, especially since Aguilera has one of the strongest vocal instruments in pop today. She was prodigious on tween debut hits Genie in a Bottle and What a Girl Wants; she was unrivaled on her career highlight, 2006 double album Back to Basics, a smoky, brassy neo-throwback experiment gone right. That LP included the Andrews Sisters moxie of double-entendre doozy Candyman and a winking tribute to her then-husband called Ain't No Other Man. Again, those were super-sexy cuts, but they were also fun and upbeat and original. It's nice when Aguilera remembers true heroes like Etta James and Aretha Franklin — or even Whitney for that matter.The strongest tracks on Lotus turn out to be duets with her act-naturally pals on The Voice. A midnight croon with Blake Shelton, Just a Fool, has a chance of being a mondo hit, her nuanced, octave-spanning mixing well with his gritty country plea. And there's a sly Mickey Mouse Club joke (she was a member) at the start of the slammin' steam-punk of Make the World Move, an R&B throwdown with Cee Lo.Aguilera is too talented, and hopefully too smart, to continue down this wasteful path. And yet, it's troubling that she wants to compete with the unworthy Ke$has of the world when the hottest artist in music — with kids, with adults, you name it — is Adele, who uses genuine emotion and a genuine voice to get her bluesy point across. Can Xtina wail better than Adele? That's debatable, but that we could have a genuine debate says a lot. Drop the grudges and the desperate party cuts, Christina, and let's get back to basics.Sean Daly can be reached at [email protected] Follow @seandalypoplife on Twitter.