By Jim Roberts

Halfway through a 20-minute phone interview—about eight of them spent talking about politics—Nellie McKay stopped herself and asked: “How much of the human body is water? Is it 70 percent? … Well, even more of a percentage of our show is music. It’s 95 to 99 percent.

“But then you have to try to put in a few yuks,” she added. “You’ve got to keep it happy, you know? We definitely aim to entertain, and I hope more often than not, we do.”

The 35-year-old has been described by All Music as a “21st century bohemian folksinger who deals in offbeat piano pop with light Broadway and punk leanings.” In other words: Her music and her shows can be diverse. And since she also has experience doing stand-up comedy, the yuks come pretty easily.

McKay’s career in music started with a bang. After dropping out of the Manhattan School of Music, she was signed to Columbia Records and released a double album, “Get Away From Me,” to rave reviews in 2004.

It helped that she collaborated with Geoff Emerick, an engineer who had worked with the Beatles at Abbey Road Studios. “He just knows how to twist those knobs,” McKay said. “He can make something sparkle. … We feel like we’re all on a yellow submarine together.”

Fame was also sudden, thanks to her television debut: a performance of the quirky “Dog Song” on “Late Show With David Letterman.” “I just wished I could have sat on the couch and talked to him,” she said of the talk show legend. “But he came over like a friendly alien. … It was a delight.”

Paradoxically, she hasn’t significantly built on the popularity she first enjoyed 13 years ago. Consider this concert review from 2015: “Nellie McKay is one of those artists you’ll be glad you saw on the way up,” Shawn Mullen wrote in The Moderate Voice. “This is because McKay’s star is burning brightly these days, and she is going to be very big.”

While she appeared on Broadway in “The Threepenny Opera” in 2006 and in the film “P.S. I Love You” in 2007, her five albums since “Get Away From Me” have positioned her in a progressively smaller niche. Her second and third albums were released on her own label, Hungry Mouse, and her fourth was “Normal as Blueberry Pie,” a tribute to Doris Day. Her last record, 2015’s “My Weekly Reader,” is a collection of covers from the 1960s. Other than the Beatles’ “If I Fell”—now a fan favorite at shows—the song choices are mostly obscure, like Frank Zappa’s “Hungry Freaks, Daddy.”

She’ll draw from all of these sources—and a forthcoming album of “standard saloon songs”—when she performs in Norfolk in December. “I’ll be previewing a little bit of that,” she said. “But then we usually take some requests. People can just heckle. We’ll try to mix it up.”

McKay has never played Norfolk, but she did come down from New York for a short internship at People for the Ethical Treatment of Animals when she was a teen-ager. “That was a wonderful time,” she recalled, “and it really made an impression on me. … Those undercover investigators, they’re heroes. I don’t know how they do what they do.”

Don’t be surprised if she tells a PETA story or two at her show—or if she gets more overtly political. “There is a lot of hope,” she said. “I mean, more people, they are aware of what the government is doing now. … I actually think it’s very positive.”

Nellie McKay will perform at 8 p.m. Dec. 2 at the Virginia Arts Festival’s Robin Hixon Theater in Norfolk. The show is part of a series co-presented with North Shore Point House Concerts. Tickets are $30. For more information, visit vafest.org.