Rosemary Doyle, left, and Lisa Horner discover love in My Mother's Lesbian Jewish Wiccan Wedding. (Lindsay Anne Black/Mirvish Productions)

I'm standing in Toronto's Panasonic Theatre, where the entire cast of the musical My Mother's Lesbian Jewish Wiccan Wedding is immersed in rehearsal. The actors, outfitted with personal body microphones, are walking around on stage. Offstage, assistant dressers are waiting in case they need to help with a quick costume change.

My Mother's Lesbian Jewish Wiccan Wedding moved from the Fringe festival to the "A-house" when it caught the attention of David Mirvish, the man behind recent mega-musicals like Dirty Dancing and The Sound of Music.

It's the beginning of the show's "tech week," when all the lighting, sound cues and volume levels are sorted out. Boyish-looking director Andrew Lamb sits at a table in the middle of the theatre surrounded by his production team. Lamb is luxuriating in this rehearsal, which will be followed by a week of previews to work out any technical kinks. It's a far cry from the Toronto Fringe Festival, where the musical debuted. At the Fringe, "tech week" is more like "tech three hours," and personal body mics are an unheard-of expense.

My Mother's Lesbian Jewish Wiccan Wedding is an autobiographical musical written by David Hein and his wife, Irene Carl Sankoff, who also perform in the show. Hilarious and heartwarming, it's based on the story of Hein's mother, who came out to her son while he was in high school. Underneath the family comedy is a strong message about gay rights.

The play started on the tiny stage of the 85-seat Bread and Circus theatre in Toronto's Kensington Market. Now, it's about to become a full-scale Mirvish production.

"I can finally realize my vision," marvels Lamb with a rich chuckle. "We can afford sound and lighting effects this time around, and the actors can all actually fit comfortably onstage!" The stage at Bread and Circus is less than 200 square feet, a tight fit for a cast of seven plus a three-piece band.

The musical has now moved to the "A-house," an industry term referring to a larger-size theatre and union rules that enforce better treatment of actors. Playing a venue like the Panasonic Theatre is every Fringe artist's dream. For Hein and Sankoff, it became a reality when their show caught the attention of David Mirvish, the Toronto theatrical producer behind recent mega-musicals like Dirty Dancing and The Sound of Music. It started when John Karastamatis, director of communications for Mirvish Productions, caught My Mother's Lesbian Jewish Wiccan Wedding at the Fringe.

"It's the first show I've seen since The Drowsy Chaperone with [the same] kind of commercial appeal," says Karastamatis. "It was clever, heartfelt and honest, and it just told a really good story." Formerly a president of the Toronto Fringe Festival, Karastamatis was the one who recognized the post-Fringe potential of The Drowsy Chaperone, and produced that show's first remount at Toronto's Theatre Passe Muraille. "When I told David that he needed to see [My Mother's Lesbian Jewish Wiccan Wedding], he listened," Karastamatis says. Not only did he listen, but Mirvish happened to have a hole in his fall schedule.

Playwright David Hein, right, turns autobiography into musical comedy with co-star Lisa Horner in My Mother's Lesbian Jewish Wiccan Wedding. (Lindsay Anne Black/Mirvish Productions)

The Drowsy Chaperone took a full decade to get from Fringe to Broadway. My Mother's Lesbian Jewish Wiccan Wedding has had less than four months to make the transition from playing in the back of a bar to a 700-seat theatre. These few months have been a whirlwind of rewrites and rehearsals for Hein, Sankoff and Lamb, as well as the rest of the cast and crew, all of whom have been retained for the Mirvish production.

"It's definitely a challenge to spin around and make something worthy of 'A Mirvish Production,'" admits Sankoff during an hour-long lunch break from rehearsal. She and Hein were charged with the task of adding a new half hour of content to their original, 60-minute musical.

"It's the same show, just more," explains Hein. "More character development, more songs, more cast members."

Most of the changes were written before rehearsals began, but having the writers in the show means that some rewrites happened during the rehearsal process. The regular pressures of the rehearsal schedule are increased by a myriad media obligations, though the attention seems to agree with Hein and Sankoff. At a recent press event, Sankoff beamed as she and Hein were swept around the room from camera to camera, doling out gracious sound bytes. TV cameras aside, the biggest difference with this production is the luxury of time: no one is rushing to rehearsal, exhausted from their day job. This is their day job now.

This is obviously a great career opportunity for everyone involved, but Andrew Lamb is particularly excited that the show's pro-gay marriage message will find a wider audience.

"I was originally drawn in by the political aspects of this show," he explains. "There's one song, A Short History of Gay Marriage, that is the most important number to me. I feel so proud that we can do a show with this theme in this country, and that it's safe, because there are many places where My Mother's Lesbian Jewish Wiccan Wedding could not be performed. And I really feel passionately that this show should be viewed by as wide an audience as possible."

My Mother's Lesbian Jewish Wiccan Wedding runs in Toronto from Nov. 15 to 29.

Alison Broverman is a writer based in Toronto.