'Liberation' review: Christina Aguilera's intermittently great comeback

Blessed with one of the most enormous voices in pop, Christina Aguilera has struggled in the 19 years since her breakthrough smash “Genie in a Bottle” to find the right material and sound to fit the times and her personality. With “Liberation” (RCA), inspiration arrives in spurts — “Sick of Sittin’ “ sounds like a lost live Big Mama Thornton track from the late ‘60s, a burst of psychedelic soul full of chants and vamps and screeching electric guitars, and “Like I Do” is a super-modern ballad built on a flute-y synth riff and sexy lines like “we can Marvin Gaye and get it on” and “you’re so much better when you don’t speak.”

Aguilera sings impeccably on every style she assigns to herself, from the opening extrapolation of “Maria” from “West Side Story” (which turns into an R&B jam with a sample of Motown-era Michael Jackson), to the blow-the-house-down duet with Demi Lovato on “Fall In Line.” She manages the busy “Accelerate,” which required 13 songwriters, including Kanye West, and raps from both Ty Dolla $ign and 2 Chainz, reasonably well, although she’s clearly more comfortable on the stripped-down ballad “Twice,” which contains just Aguilera, a piano and some backup vocals.

It’s not unusual in today’s pop for a star singer to rely on multiple songwriters and collaborators — Beyoncé made her masterpiece “Lemonade” this way. But Aguilera has never been visionary like Beyoncé or Gaye. On “Dreamers,” young girls declare they want to be screenwriters, superheroes, a boss, the boss. Aguilera never expands this powerful spoken sentiment into a coherent thesis; as always, impeccable singing will have to do.