She’s taking yet another direction

It’s unlikely that any major artist has done more to complicate confessional singer-songwriter music than Tori Amos. When she emerged in 1992 with “Little Earthquakes” -- her solo debut following a stillborn effort by a glam-pop group unfortunately named Y Kant Tori Read -- Amos set her tales of sexual alienation against stark piano-based arrangements that emphasized the raw honesty of her writing.

Since then, though, Amos has steadily moved her music away from those unadorned roots, toward something weirder and far more idiosyncratic. She’s folded into her sound sleek electronic textures, lithe funk beats and noisy punk guitars, and lyrically she’s often exchanged straightforward first-person accounts with the shifting perspectives of narrative role-play.

Still, Amos’ music remains a life preserver for listeners desperate for the appearance of emotional authenticity; her intensely devoted fans cling to her like shipwreck victims adrift in a frigid sea of Fergies and Nelly Furtados.

Sunday at the Nokia Theatre, Amos and her three-piece band played the final date of a two-month North American tour in support of “American Doll Posse,” Amos’ latest studio disc, on which she channels several alter egos in an attempt to “reclaim the segmented pieces of the female psyche,” as she has said.

Though its concept isn’t her most clearly enunciated, “American Doll Posse” contains some of Amos’ best work in a few years, and on Sunday, after about an hour of meandering (and two wardrobe-and-wig changes), she hit a confident stride that echoed the album’s tuneful thrust.

The closest thing she’s got to a radio single these days, “Big Wheel,” brought the night’s most appealingly audacious moment, with Amos leading the audience in an unlikely, bawdy singalong while her band (anchored by the nimble drummer Matt Chamberlain) chewed over a chunk of rowdy Southern riff rock.

“Cornflake Girl,” one of Amos’ signature songs, rode a deep R&B; groove. “Amber Waves,” from 2002’s 9/11-inspired “Scarlet’s Walk,” sounded like vintage soul remade for the Information Age. The new album’s “Bouncing Off Clouds” throbbed with the forward momentum of disco.

Near the end of her two-hour set, Amos performed two songs by herself, including “Silent All These Years,” which first cemented her reputation as the austere balladeer she no longer is. True to her evolution, she overhauled the tune with bizarre line readings and new rhythmic nuances, creating something strange and powerful in equal measure.