“I swear, I grew up like I was from another era,” said Ms. Birch, 30, the daughter of a Seventh-day Adventist minister who moved his family around the world, with stops in Michigan, Zimbabwe and South Africa before settling in Portland, Ore., when she was 10. “My mother and father were 20 years older than my friends’ parents, and they were incredibly religious, so while I’m definitely not conservative or traditional by any means, I am, in a sense, a little old-fashioned.”

She added, “Besides, lots of times, I gravitate to things that are really old-fashioned, because in my mind I think that they’re so ahead of the game.”

Bridging both worlds, Ms. Birch is about to release an album that puts much of the last half-century of pop music through a blender in a way that sounds modern and fresh. Titled “Speak a Little Louder” (S-Curve Records), it features piano ballads, R&B and funk mingling with a pulsing update of ’90s synth pop, with layered vocals drizzled atop much of the album. That musical adventurousness is reflected in two high-profile appearances this year, at the Prince tribute at Carnegie Hall in March and last month, when she joined Elvis Costello and the Roots at Brooklyn Bowl to duet with Mr. Costello on a song from “Wise Up Ghost,” the album they just released.

The new album is a follow-up to her acclaimed 2009 debut, “Bible Belt.” Ms. Birch had little radio airplay with that album’s single “Nothing but a Miracle,” but she nevertheless performed on most of the late-night talk shows. She quickly gained a legion of high-profile supporters including Prince, Dave Stewart of Eurythmics, Daryl Hall, Mark Ronson, Ne-Yo and the Roots. She ate sashimi with Mick Jagger and opened for Stevie Wonder. Ms. Birch had, in effect, arrived before most people had even heard of her.

And just like that, she was gone again. At a time when artists normally try to capitalize on their momentum, she receded from public view and didn’t reappear with a new batch of songs for almost four years, because of a combination of writer’s block, dissatisfaction with the works she was producing and personal loss — coupled with dealing with the crushing expectations that usually do not accompany artists who have sold just over 72,000 copies of their debut album.

Musically, her new release is less rooted in a particular era than “Bible Belt,” which drew inspiration from the 1960s and ’70s. But lyrically, it advances some themes from its predecessor, like the simultaneously confining and liberating qualities of pain and the paralysis brought about by self-doubt.

“I desperately wanted to show another side of myself,” Ms. Birch said over tea on the terrace of a cafe in the meatpacking district. “I had been so pigeonholed from ‘Bible Belt.’ ”

For “Speak a Little Louder,” Ms. Birch, who in conversation uses a variety of sound effects to simulate things like a radio being toggled between stations or a needle hitting a vinyl record, and whose personal style could be described as “coven meets couture,” wrote songs with the soul singer Betty Wright, Matt Hales (who records as Aqualung) and Eg White, who has worked with Adele and Joss Stone. Mr. Hales and Mr. White also produced their tracks.

The new album’s first single, “All the Love You Got,” is an amalgam of the album’s most common musical threads, including gospel-flecked background vocals and a propulsive backbeat, in this instance provided by the bassist John Taylor of Duran Duran and the drummer Questlove of the Roots. “I heard that demo, and it was irresistible,” Mr. Taylor said. “I just thought, ‘I’ve got to get on this fantastic song one way or the other.’ ”

Although she continues to attract admirers, Ms. Birch has not been without her detractors. They considered “Bible Belt” an imitation of Laura Nyro and Carole King, whose “Tapestry” is widely considered the benchmark album for female singer-songwriters.

“To be honest with you, I hadn’t heard ‘Tapestry’ until six months before I got a publishing deal in the U.K. in 2007,” Ms. Birch said. “In this business, people put you in a little box: You have brown hair, and you play piano, you’re like that.”

After nearly two years of touring, during which she’d been called “everything from indie to electro to country, folk, gospel and soul,” Ms. Birch said, she went into the studio to record the follow-up to “Bible Belt.” She developed an obsession with the disco producer Giorgio Moroder and harbored a nascent desire to record a disco album, which was at odds with much of the music she had already written. So she began to experiment with new sounds and textures. Songs she was unable to retrofit were jettisoned. She embarked on a “miserable” monthlong writing stint in London, which resulted in her first single, but little else.

“I would get 20 different song ideas a day,” Ms. Birch explained. “It was insane. I would be like: ‘Come on, give me a break. Don’t give me 20. I just want one.’ ”