Grimes already defied easy classification on Visions, a collection of dreamy electronic collages that resembled pop just enough to make it one of 2012's most acclaimed albums.

When she returned three years later with Art Angels, her music was even more paradoxical; Claire Boucher's fourth album is wilder, more ambitious, and -- at least on the surface -- more accessible than her breakthrough.

This time, Boucher's production draws attention to all the sounds and styles she's juggling: "laughing and not being normal" begins things with symphonic pomp, its trilling vocals, piano filigrees, and pizzicato strings signaling that this album is an event.

"SCREAM," a fiery duet with Taiwanese rapper Aristophanes, incorporates drumline-tinged beats -- as well as Boucher's spine-tingling howls -- into its iconoclastic feminine power, while "Easily" and "Artangels" touch on different but equally shiny flavors of late-'90s pop without a trace of irony.

Elsewhere, "World Princess, Pt.

2" and "Venus Fly," which features Janelle Monáe -- one of the few artists who rivals Grimes when it comes to high-concept, utterly catchy music -- bring Visions' R&B leanings to the fore.

It could all lead to sonic whiplash, but Boucher's staunchly independent viewpoint is the glue that holds together Art Angels.

She matches the album's bolder sounds with songwriting that's more daring and, at times, more aggressive.

On "Kill V.

Maim," she combines her perkiest vocals and angriest lyrics, topping beats that land like bombs with cheerleader-like chanting.

A reworked version of "Realiti" underscores how driven she sounds here; her declarations of independence are catchier than ever, blending the cute and the formidable until they're one and the same.

Similarly, Boucher explores how destruction and creation are joined at the hip in vivid, hooky songs like "Flesh Without Blood," where ending a relationship means self-preservation, and the standout "California," where bliss and disaster meet ("When the ocean rises above the ground/Maybe I'll drown") with an unexpected but very welcome twang.

"I'll never be your dream girl," Boucher sings on "Butterfly," but she adds "you could be anything," making the connection between honoring yourself and ignoring others' expectations clear.

She does both consistently -- and consistently well -- with Art Angels' truly independent pop.