From Philadelphia to Stockholm, Sweden, it's 4,003 miles - a gap that narrows Dec. 27-31 when the national company of ABBA's upbeat jukebox musical smash Mamma Mia! brings its "Farewell Tour" to the Merriam.

For those just recently arrived on this planet, Mamma Mia! is a musical created by ABBA composers Björn Ulvaeus and Benny Andersson, weaving around a bunch of ABBA hits the tale of a free-spirited mom trying to guess which of her three former paramours is the father of her daughter. Philadelphia is well represented in the upcoming theatrical road show. The upcoming show has an Allentown native as one of its leads (Parkland High grad Lizzie Markson as Sophie), and Barrymore Award-winning thespian Pearce Bunting spent eight years and 1,600-plus performances playing Bill, one of Mamma Mia!'s male leads, between Broadway and its initial national tour.

"The idea of me in an ABBA musical was so outlandish, I had to try," says Bunting, last seen locally in 2015's Who's Afraid of Virginia Woolf? at Theatre Exile. "It turns out they were looking for character actors who could 'sing' and do a passable Aussie accent." Bunting was chosen for the national tour in 2001 then joined the Broadway cast in Fall 2005 for another three years.

"In no way was I an ABBA fan in the '70s," says Bunting, who grew up as a fan of the Grateful Dead, Miles Davis, and the Mahavishnu Orchestra, and of the drama of Ibsen and Ionesco. You would not have predicted for him eight years singing chipper bazillion-sellers such as "Chiquitita" while dancing on Broadway.

But Bunting understood the magic of Björn and Benny - the two B's of ABBA, its A's being singers Agnetha Fältskog and Anni-Frid Lyngstad - once he learned its history of hits pioneered through a multilayered recording process in which everything was present, up front, in the mix. Those in-your-face catchy tunes were feel-good anthems to a gentler, happier '70s.

"Mamma Mia! was the first show to open on Broadway after 9/11," recalls Bunting. "New York City was a serious, delicate place then, and most of us had forgotten how to laugh. Everybody needed permission to lighten up, and Mamma Mia! gave that to us. A lot of people who hated ABBA - yes, like me - were totally drinking the Kool-Aid and dancing in the aisles at the Winter Garden."

 That infectious sound and energy was just the thing that brought Allentown's Markson to ABBA. She was a theater kid at Parkland High who loved singing Betty Comden and Adolph Green tunes. "But the funny thing was that I was listening to a CD of the A-Teens and songs like 'SOS,' and though that was [an ABBA song], not realizing that they were just a Swedish kids' tribute act emulating their idols," she says with a laugh. "I grew up jamming hard to this cool fake version of 'Dancing Queen.' "

Before graduating Elon University in North Carolina with a BFA in Music Theater in May 2016, Bunting did a set of Broadway auditions in March of that year - and caught the attention of New York casting director Joy Dewing. Three weeks after graduation, Markson got the part of Lizzie and began living in ABBA World, where distinct phrasing and elocution are key. The ABBA style must be maintained throughout Mamma Mia!

"We found quickly that it's important to ABBA's members to do the songs in a way that's true to their sound and intent," says Markson of the learning curve. "That was crucial to their success. In approaching each song, we must pay close attention to the specifics of each syllable and note, and not add extra style or personality - which is tough, as I have a tendency to add a little scoop to my phrasing. But I got it."

The sound of ABBA is clear, direct and regimented. According to Mamma Mia! music director Kevin Casey, that's because Ulvaeus and Andersson wrote their songs for the radio instead of the stage. "That means more straight tone, sliding between notes, breathiness, etc. than you'd hear in a standard musical," says Casey. "Before we teach each number, the cast listens to the originals for reference to replicate the layered vocal sound ABBA is known for. There are cast members, too, singing from backstage during every track."

Bunting agreed that the music is "tight, tight, tight, with singers backstage doing strict backup harmony, completely crafted and conducted, with the show reviving that ABBA vocal sound, like a Swedish Frankenstein monster in platform boots." As a non-singer, however, he found his own way of making it his own. "Like burping on stage," he jokes. "They loved that."

Markson has also found her own way into Mamma Mia! Rather than letting it be "a cookie-cutter experience, I lose my truth in the story," she says. "I'm still that kid belting out 'Dancing Queen' when I hit the stage."

The Mamma Mia! Farewell Tour plays Tuesday through Saturday at the Merriam Theater, 250 S Broad Street. Tickets: $40-$102. Information: (215) 670-2300, Kimmelcenter.com