Ernest Shackleton, intrepid British explorer and leader of three early expeditions to the Antarctic, was not a likely subject for a musical.

That is, until married composer-musicians Valerie Vigoda and Brendan Milburn saw a major exhibit about him, and with Broadway writer Joe DiPietro (“Memphis”) and noted director Lisa Peterson (“Pullman Porter Blues”) conjured him in “Ernest Shackleton Loves Me.”

The Balagan Theatre show is premiering now at Seattle Rep.

“Brendan and I became a little obsessed with Shackleton,” declared Vigoda, in an interview before the show opened in Seattle.

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Added Milburn, “He was indefatigable. We really admire his resilience. And bringing every one of your men back to civilization after they’d been out on the ice for 22 months is extremely bad-ass.”

Historical context: During the Imperial Trans-Antarctic Expedition of 1914-17, Shackleton’s ship, Endurance, became trapped in the ice during an attempt to cross the Antarctic.

The musically eclectic, Los Angeles-based couple (who have an 8-year old son) have paid the bills writing stage versions of animated Disney shows, such as “Toy Story.”

They also perform together in their own “theatrical power pop” band Groovelily. But “Shackleton” was initially conceived as a solo piece.

“Many solo shows are memoirs. They can be beautiful and resonate, but we wanted something adventurous and epic,” recalled Vigoda.

The format changed when, working with DiPietro and Peterson, they brought Shackleton into the multimedia stage picture, which incorporates documentary film of the actual Endurance voyage and imagines a time-traveling relationship between the explorer and a modern fan.

“We tried to modulate my voice through technology to make me sound like a man,” Vigoda said, “but it sounded creepy.” Now actor-singer Wade McCollum (who recently was seen in Seattle as the co-star of the touring musical “Priscilla, Queen of the Desert”) plays Shackleton, and several other male roles.

Vigoda portrays a harried avant-garde music composer and single mom who communes with the explorer. Vigoda also sings, plays electric violin and does some “live looping — laying music down and recording over it” during the production.

But Vigoda’s favorite instrument in the score is the banjo. An Endurance crewman brought one along, and Shackleton called it “a vital mental tonic.” (There’s now a Shackleton line of banjos made in England.)

First commissioned by TheatreWorks in Palo Alto, Calif., the musical now has the enthusiastic backing of indie producer Matthew Kwatinetz, who ran Seattle’s now-defunct Capitol Hill Arts Center.

The hope is to bring “ Shackleton” to New York eventually, acknowledged Milburn. “Matthew is looking at nontraditional venues. Maybe we’ll hand out parkas at the door!”

Misha Berson: