The two who made ‘Six,’ by melding pop divas and Henry VIII’s wives into a sassy musical

Andrea Macasaet (center, as Anne Boleyn) with the cast of “Six.”Liz Lauren

For Toby Marlow and Lucy Moss, the possibility of disaster loomed large at the advent of their new musical “Six.” When Marlow, then a student at Cambridge University in England, first proposed writing a tongue-in-cheek, pop music-inspired show about the six wives Henry VIII, his friend and classmate Moss was skeptical. Sure, the dangers weren’t the kind of perils faced by the tossed-aside queens who had the misfortune of marrying the toxic Tudor king and whose fates were infamously reduced to the classroom refrain, “divorced, beheaded, died, divorced, beheaded, survived.”

Marlow’s brainstorm was to stage the female-empowered show as a pop concert-turned-singing competition featuring each of the queens — Catherine of Aragon, Anne Boleyn, Jane Seymour, Anna of Cleves, Katherine Howard, and Catherine Parr. Their musical styles would be drawn from Marlow and Moss’s mutual love of pop stars like Beyoncé, Ariana Grande, Rihanna, Lady Gaga, Adele, and Sia.

“I remember agreeing and being like, ‘Yeah, yeah, sure!’ But then equally being like, ‘That could be so bad!’ ” Moss says, speaking on the phone with Marlow from London.

Sure, “Hamilton” had successfully employed hip-hop to tell the story of America’s Founding Fathers. But Marlow’s irreverent historical concept was fraught with the possibility that the entire enterprise could devolve into cheeky anachronism gone awry, excessive snark, or misguided parody.

Still, what did they have to lose by taking the leap? Besides, she never imagined it would go anywhere. “I figured I’ll just say yes and then we’ll write it, and I’m sure it’ll just all crumble to pieces,” she says.

Instead, to Marlow and Moss’s great surprise, those pieces cohered brilliantly into a show, “Six,” that’s been on a meteoric ascent ever since it debuted two summers ago at Scotland’s Edinburgh Festival Fringe. On Wednesday, it arrives at the at the Loeb Drama Center in Cambridge for a five-week run to open the American Repertory Theater’s season.

After opening to considerable buzz for a limited run in London last fall and receiving warm reviews, it returned to the West End in January and continues to play to packed houses. Earlier this year, the musical had a wildly successful stateside debut in Chicago. Next February, “Six” makes the big leap to Broadway after playing two more North American cities in the fall. “It’s been so crazy over the last two years watching everything explode,” Moss says.

Just getting “Six” staged at the Fringe, let alone the show becoming a festival hit, was enough of a triumph for two budding theater-makers with no professional experience. “We achieved our end goal pretty quickly,” Marlow says. “When people came to see it, I was like, ‘Oh my God, we’ve made it!’ That, to me, was phenomenal. We managed to write a show, put it on, our friends liked it, audiences liked it.”

Indeed, just a few short years ago, Marlow and Moss, now 24 and 25 respectively, were a pair of pop music-loving students at Cambridge. When they’d get together, they’d watch dance videos on YouTube and laugh hysterically. “We’d scream and dance along and then drink wine and go clubbing,” says Moss.

Laughter is also in abundance when they recall, reluctantly but giddily, the time they stood outside a party, slightly tipsy, as Moss shouted “Kiss me!” and Marlow, who’s gay, enthusiastically obliged. Both of their eyes widened in shock, followed by falling-on-the-floor laughter. “And . . . never again,” Moss deadpans. Still, their friendship remains as electric as ever.

The duo met during their first few weeks at school. Marlow had gone to see a show that Moss had directed at the student theater and introduced himself afterward. A few weeks later, he auditioned as an actor for another show Moss was directing, and they became fast friends. “But I was a fan first and foremost — and still am to this day.”

The next year, they worked together on a musical-comedy pantomime. Marlow had composed the songs, and Moss remembers being completely awestruck. “I sat there with my jaw on the floor, being like, ‘Oh my God, this is the most insane songwriting I’ve ever heard,’ ” she says.

“Six” began when Marlow learned that Cambridge University’s Musical Theatre Society wanted to take an original show to the Edinburgh Fringe. He submitted a proposal to write a historical musical using pop music, and it got accepted. But then he had to actually write the show. One day, while daydreaming in a poetry class, the idea came to him. “We wanted to have pop music and a famous subject matter,” Marlow says, “because there’s thousands and thousands of shows at the Edinburgh Fringe, and original shows need a hook to get the audience in.”

Writing in the pop idiom posed a challenge because musical-theater songs have to tell a story, while “pop songs are often about one moment or one feeling and they require a specific structure,” Marlow says. “But then it became fun to subvert or play around with pop song form to tell stories.”

Each queen in the show has a different sound, personality, and look that are influenced by a mix of pop stars beloved by Marlow and Moss. “The concert form was also helpful because it meant we could step outside their stories and have this meta-narrative,” Moss says, in order to fill in the blanks about their history, their lives, and their reputations.

For example, Katherine Howard, the fifth wife, was an attractive young lady-in-waiting chosen by Henry when she was 16. Brought down by gossip that she was cheating on him, Howard gets an Ariana Grande-Britney Spears-style anthem called “All You Wanna Do.”

“She’s known as the frivolous one who slept around and got her just deserts in being beheaded because she was stupid enough to cheat on the king,” Moss says. “But by the end of the song, we’ve actually reframed it as her being an abused child who has been taught by all the people around her to behave in a certain way. It’s about, why doesn’t anyone value me for anything other than my body and my sexuality?”

With Broadway on the horizon and new songwriting deal with Warner Chappell Music, Marlow and Moss say they’re trying to remain grounded. Whenever they see “Six,” Marlow says they worry that this will be the time they realize the show “isn’t actually that good” or “doesn’t resonate anymore.”

Still, the experience of creating a show for the Fringe at such a young age and having it go to Broadway in less than three years “has really distorted our perception of how quickly people can write shows and get them produced,” Moss says. “It’s really ruined our expectations forever.”

SIX

Presented by the American Repertory Theater. At Loeb Drama Center, Cambridge, Aug. 21-Sept. 29. Tickets from $25, 617-547-8300, www.AmericanRepertoryTheater.org