“Ernest Shackleton Loves Me,” the elaborately quirky new musical premiering at Seattle Repertory Theatre’s Leo K. venue, has one winter-booted foot in present-day, artsy-bohemian Brooklyn.

And it has another foot thousands of miles away, in the Antarctica of a century ago.

Merging the two makes for a 90-minute voyage that’s visually impressive, sonically inventive and whimsically diverting — when it isn’t, well, overly earnest and a bit sappy.

The brainchild of musician-composers Valerie Vigoda and Brendan Milburn, staged by noted director Lisa Peterson on a nifty set by Alexander V. Nichols, this is the latest production from the enterprising Balagan Theatre. And the show is certainly one of a kind.

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Scripted by Broadway writer Joe DiPietro, it is set inthe frigid Brooklyn digs of Kat (Vigoda), a scruffy experimental-music composer.

As she works on her video blog, with constantly morphing phantasmagorical images projected on a massive screen that dominates the set, we quickly learn that the massively sleep-deprived Kat is: 1) strapped for cash; 2) the mother of a colicky infant, who periodically wails from offstage; and 3) without a mate, since her no-goodnick musician boyfriend went on the road with a Journey cover band. (Ouch.)

A likable enough actor, Vigoda is a rousing singer and laudable electric violin player, and the several blazing rock tunes (“This Sucks,” “Stop Rewind Play Record,” “Burned Again”) she co-composed and overlays with electronic effects, are highlights of the score.

As Kat freezes her tootsies off in her polar vortex of an apartment, she blogs her latest video-game music composition (an imposingly layered, synth-symphony) and bemoans her lot.

What this girl needs is a new job, a new romance (maybe) and an inspirational mentor (definitely).

The latter arrives, on screen and in the flesh, in a dashing hallucination of explorer Ernest Shackleton — who, as we know, journeyed to Antarctica in the early 1900s, and whose exploits are the stuff of lore, legend and cult status.

Played with jolly good humor and rollicking flair by Wade McCollum, Ernest is summoned as an eminent Victorian, and a chipper goofball who loves to ”hootenanny” while strumming on a banjo and singing “It’s a Long Way to Tipperary.”

But he’s also a dauntless adventurer into parts unknown. And when he takes Kat along on a momentous, Outward Bound-ish voyage, the multimedia design incorporates some spectacular black-and-white film taken by a crew member during Shackleton’s Imperial Trans-Antarctic Expedition.

Shackleton failed a century ago to make the first land crossing of Antarctica. But his effort lived up to the name of his ship, the Endurance. Under near-impossible odds, the entire crew survived a winter with their vessel packed in polar ice, which marooned them in subzero temperatures with scant provisions and little hope of survival.

After the ship split apart and sank, the intrepid, steadfast Shackleton and several of his men made a daring voyage in a lifeboat to find help, eventually rescuing all his men (and after other trying adventures) returning them to England, safe and sound.

This is a mere outline of the detail the show goes into, as Kat and Ernest use ropes and cargo boxes to re-enact the voyage, and the grainy, black-and-white footage of glaciers, penguins, sea lions and the majestic, doomed Endurance sweeps us into a vividly dramatic travelogue.

Briskly and artfully staged by Peterson, with technical direction by Ahren Buhmann, the production synchronizes its film and live elements with great aplomb.

However the musical, which unfolds in one act, loses satirical snap and some verve as the warm relationship between the explorer and his ardent admirer veers toward the mawkish. And the music grows repetitive when it leans too heavily on sing-songy sea chanty tropes.

Shackleton (whose leadership style is now studied in business schools) becomes a role model of courageous persistence for Kat. But the idolatry can get sludgy-sweet, as this jaunty superman also inspires her to become a better mommy and to ditch the loser boyfriend (also played by McCollum), the butt of too many dumb-rocker jokes.

There can be no doubt, however, that “Ernest Shackleton Loves Me” is unique, or that the creators have woven techniques formerly associated with avant-garde performers like Laurie Anderson, into a mainstream pop musical — aimed, and steaming, according to a program note, toward Broadway.

Misha Berson: mberson@seattletimes.com