I was trying to think of an analogy for the role Nancy Anderson plays in "The Pajama Game," the musical that's at Arena Stage through Dec. 24.

Not Nancy's role in the cast — she's Gladys, the factory boss's secretary — but the odd bit of family history she brings to the part. Let's see: It's sort of like if Nancy's great-grandfather had been an itinerant trombone salesman and she was in "The Music Man." Or her great-great-grandfather had been a Cockney flower seller and she was in "My Fair Lady." Or her great-great-great-great-great-great-great-(etc.)-grandfather had been a knight of the Round Table and she was in "Camelot."

Nancy is the great-granddaughter of Orrice Abram Murdock Jr.

Okay, so that may not have the same cachet as being descended from Sir Lancelot, but it is a particularly fitting bit of Washington wonk heritage.

Democrat Abe Murdock was a three-term U.S. representative from Utah who then served a single term in the U.S. Senate. In 1947, President Truman nominated Murdock to a seat on the National Labor Relations Board, the federal agency that oversees workers' rights and polices unfair labor practices.

That's apropos, given that 1955's "The Pajama Game" is about a bitter contract dispute at the Sleep-Tite Pajama Factory.

There was partisan grumbling about Murdock before his confirmation hearings, with some GOP senators questioning his impartiality.

"Ever since [Murdock] was first elected to Congress in 1932, he has been an ardent champion of labor," Arthur V. Watkins, the Utah Republican who took his Senate seat, said in a committee hearing.

Joseph H. Ball of Minnesota complained that when Murdock was a senator, he had been unsympathetic to the Taft-Hartley Act, which cracked down on some union activities. Nevertheless, Murdock was confirmed and served a decade on the board.

Said Nancy: "He was known as 'Abe the Dissenter.' All these labor rags from the 1940s and 1950s were talking about their hero, Abe the Dissenter."

Nancy grew up in a strong union family. Her father was a musician who "wouldn't even play a church without getting a union wage," she said. And as a professional thespian, she's a member of two unions: Actors' Equity and SAG-AFTRA.

Nancy's grandfather — Abe's son William — was a lawyer who handled labor disputes. When Nancy was going through some old family papers, she found letters from William recounting his experiences.

"I realized that everything that this play is about was in these letters," she said.

The correspondence starts in 1942 with idealistic missives about the value of a strong union. Two years later, William sounded disappointed, having encountered union leaders who he felt were "hoodlum types" more interested in riding their own gravy train than helping their members.

"The Pajama Game" is a love story, but it's also "very pro-union," Nancy said. "People are fighting for a 7½ -cent raise."

Nancy said that as the boss's secretary, her character, Gladys, is essentially management. "But I'm not very bright, and my character is mainly there for a lot of song-and-dance relief," she said. (It's Gladys who delivers the sultry "Hernando's Hideaway.")

Some people may dismiss musical comedies as mere "light entertainment," Nancy said, but the classic American musical is often rooted in real history — real messy history.

" 'Oklahoma!' has the underpinnings of a really contentious time in American history," she said. Just think of Laurey: a single girl on the plains at the edge of the frontier.

"That's a very serious position," Nancy said. "It's why Curly and Jud are fighting over her. She's a landowner, and they want that land. Even the most frothy musical requires very high stakes. As an actor, you have to play it like it's Shakespeare."

Shakespeare with a step-ball-change.

Sweet charity

A week ago we raised the curtain on this year's Helping Hand campaign. That's where The Washington Post partners with three local nonprofits to share their stories. Here are the charities I'm shining a light on: Bright Beginnings, a preschool that helps homeless kids and their parents; N Street Village, a shelter and support network for women experiencing homelessness; and So Others Might Eat, which offers meals and more for poverty-stricken Washingtonians.

To learn more about them and make a donation, visit posthelpinghand.com.

Twitter: @johnkelly

For previous columns, visit washingtonpost.com/people/john-kelly.