At a time when women roughly her age (Pink, Britney Spears) are singing about love or sex, McKay writes about humorless feminists (her CD Obligatory Villagers) or the New York Times' iron-fisted rule ( Home Sweet Mobile Home), or sings tributes to sunny songstress Doris Day ( Normal as Blueberry Pie).
"Yeah, I can't say that there's logic to the trajectory of my career," McKay says. "Wish there was a plan."
McKay's recent activities include live cabarets ( Nellie With a Z, in honor of Liza Minnelli's Liza With a Z), as well as small theatrical shows weirdly centered on real-life characters such as Tipton, environmental pioneer Rachel Carson ( Silent Spring: It's Not Nice to Fool Mother Nature), and executed convicted murderer Barbara Graham ( I Want to Live!).
How does she choose these subjects?
"They seek me out," McKay says. "They're inescapable." Why is she attracted to musical biographies? "It's unpremeditated," she says - then claims her dog assists in all her script-writing.
As a songwriter, McKay specializes in complex topical lyrics (on, for example, gay rights or animal activism). As a singer, she has a voice pitched somewhere between Blossom Dearie and Annie Ross. As a stage presence, she's alluring, zany, and oddly innocent-seeming, even when tackling Graham's hard-as-nails demeanor or Tipton's secret life.
McKay knew about Graham - the third woman to be executed for murder at San Quentin, after a messy trial with little hard evidence - from the melodramatic Susan Hayward film I Want to Live! McKay's 2011 take is silly and sweeter than Hayward's portrayal, yet focused on serious issues of social justice. "I only knew Graham's story from the film," McKay says. "It's a tale sent from outer space. But the more you delve, the more you find the majority of her crimes were petty, that she didn't lead a violent life, and that there was a miscarriage of justice in the end. I don't believe in the death penalty, anyway."
When it came to tackling the life of environmentalist Carson, "I thought it would make great cabaret, a lighthearted look at pesticide poisoning."
And Tipton? "I didn't know Billy's music," McKay says. "I only knew his story, a mythical and a mysterious figure." Would she have been as interested in the story if he weren't a musician? "Of course, the piano thing helps," she says, "but I think the story is fascinating if he would've been an athlete or a mechanic. Billy was hardly the only musician who ever had to pass herself off as something else."
Along with using Tipton's music in tandem with her songs, McKay literally transforms herself into the male Tipton. How she does that, she won't say. As for his male persona, she says, "I think I'm a caring husband and father, a generous provider, and a willing confidant. I'm a good suitor for the women in my life."
For McKay, everyone has a story worth telling: "Just because you're not facing the gas chamber doesn't mean you're less compelling." She says she makes sure each character she performs stays in her life long after their shows are finished, songs over, costumes packed away: "I don't want to shake them. I like having each of them in my life. They've become friends."
Nellie McKay: "A Girl Named Bill: The Life and Times of Billy Tipton"
8 p.m. Sunday at Sellersville Theater, 24 W. Temple Ave., Sellersville.
Tickets: $25 and $40. Information: 215-257-5808 or www.st94.com.