You wouldn't know it from looking at her, but Casey Dienel—the self-proclaimed "really small white girl" who performs under the name White Hinterland—can rap along to T.I.'s verse in Justin Timberlake's "My Love." She can quote almost every rhyme off Outkast's Aquemini, looks up to Erykah Badu and tried to persuade co-bandmate Shawn Creeden to cover Jeremih's "Birthday Sex." But until last summer, she was hesitant to let those influences creep into her music. Dienel was scared.

"I was afraid of my voice for many, many years, so I would arrange around it instead of arranging with it," Dienel says, blushing and fidgeting with the pockets of her skirt. "I finally decided to blur the line between what I like and what I do. I've always really loved hip-hop and R&B, and secretly I would sing that way when no one was looking."

On White Hinterland's new record, Kairos, all those influences come to the forefront. While Dienel's past work was often hard to pin down—she flirted with piano-based chamber pop and released an EP sung entirely in French—her voice and lyrics were never as central as the music around them. Kairos, though constructed from odds and ends, is a slinky, minimal R&B record of direct pop songs. From the opening jam "Icarus," it's clear that things have changed: Dienel's voice doesn't just sit at the center of the song, it swirls around it, her harmonies circling the thick dub bass and interlocking drum machine groove like mosquitoes looking for the perfect bite.

The newfound confidence is also heard in Dienel's intimate lyrics, which often come off as both seductive and heartbroken on the same track. Dienel describes Kairos as a breakup record, and though the songs frequently document her indecision (writing a postcard that's never sent on "Amsterdam"; holding hope that her new love might "become the man I thought you were" on "No Logic"), they are sung from the perspective of someone who's finally comfortable in her own skin.

"In the past I would protect myself from getting too close to the subject matter in the song," she says. "I tried to be more honest with this one. I didn't want it to be some TMI situation, like John Mayer's Twitter feed, but there's also nothing wrong with a little bit of honesty."

Part of Dienel's reflection was finding out exactly what kind of songwriter she wanted to be. Dienel—who turns 25 this week—originally left her coastal home in Scituate, Mass., to attend the New England Conservatory of Music. She released her first record, 2006's Wind-Up Canary, under her own name on local folk label Hush Records before signing to Dead Oceans and releasing a full-length and EP as White Hinterland. The project's sound shifted frequently, in part because of her eclectic taste, but also because of a band lineup that was never stable.

Consistency only came with a 2008 move to Portland and a partnership with fellow East Coast transplant Creeden. Though they'd been friends for years ("He used to play the saw in a hardcore band I liked," she says, laughing), their music making was cemented last summer in producer Alexis Gideon's home studio. The trio hunkered down to create the washy backdrops and "slutty basslines" that make up White Hinterland's new sound.

For the first time, Dienel wrote songs without a piano, instead focusing on vocal melodies, aquatic synth textures, live looping, and lots of primal percussion. "No Logic," for instance, is built from an acid-fried ukulele line, with natural distortion coming from Dienel's pickup and a chopped and screwed beat that she and Creeden labored over before settling on a brisk tempo. It led to an album of singles, with each song both experimental but poppy enough to stand out.

"Our goal was to make an R. Kelly jam, only with all these odd noises in the background," Dienel says. "When you're singing you have to be willing to look a little idiotic. It just took me a while to realize that."

SEE IT:

White Hinterland plays Sunday, March 14 at Holocene with Alexis Gideon and Cole Miller. 8:30 pm. $8. 21+.