NEW YORK • A troupe of South Asian actors, assembled from across the globe, gathered in a Manhattan rehearsal room in March to enact, in song and dance, one of the signature schisms of the 20th century: the British-mandated partition of India and Pakistan in 1947, which led to the displacement of some 15 million, deaths numbering more than one million and a legacy of barely contained border tension.

As one group of actors shouted "Allahu Akbar", another answered with the Hindu chant "Har Har Mahadev".

In moves closer to stage combat than dance, the cast members clashed on the studio's sprung floor as a love story played out poetically in the foreground - or rather, the end of a love story, as a Muslim boy and a Hindu girl are forever separated by partition, or batwara.

This scene is not in the film Monsoon Wedding, the 2002 indie hit from director Mira Nair and screenwriter Sabrina Dhawan that is the basis for their musical of the same name, running at Berkeley Repertory Theatre in California until June 25.

But now is a different time, to put it lightly. What is more, theatre has different requirements than film and brings fresh opportunities.

"In India, there is so much religious strife," Dhawan said in a recent interview. But that is not the whole explanation for the new sequence: She and Nair were looking for a way to theatricalise a minor rift that troubles the film's secondary romance between a beleaguered wedding planner, Dubey, and a maid, Alice.

In the film, the two lovers have a falling out over a class-based misunderstanding, but in the musical, the authors make the dispute devotional: She is Catholic, he is Hindu. The batwara dream ballet arises when Dubey's grandmother invokes India's sectarian split as a way to warn her grandson against such division.

How does this thorny episode fit into an ebullient musical about an American-Indian arranged marriage? The Monsoon Wedding film faced a similar quandary.

Nair said she intended her film to be a "reality check" on such Bollywood trifles as the popular Hum Aapke Hain Koun..! (What Am I to You?). Inspired by those films' populist appeal and by the gritty, less-is-more Dogme 95 approach, she shot Monsoon Wedding in 30 days for about US$1 million, mostly at a friend's home in Delhi.

But Dhawan, who was a young film student at Columbia University when she wrote the screenplay - her first - remembers it differently.

"I wanted to write a movie about sexual abuse in an upper-middle- class family," she said, "and Mira wanted to do a fun wedding film. We thought, well, maybe we can put those two together somehow."

The film's abuse subplot, based on Dhawan's own experience with an older relative, is not the only conflict she revisited in writing the stage version. The concept of arranged marriage - a practice both she and Nair have avoided - also presented a new chance for revision. "I've been part of the diaspora for 20 years," said Dhawan, who was raised in Delhi, but has lived in New York City since college, "so I'm much more interested in the immigrant experience."

That is why she has changed the film's Hemant, an American groom travelling to India to meet Aditi, his arranged bride, from a first- to a second-generation Indian-American for the stage version.

If Monsoon Wedding the film aimed to offer a more realistic version of a Bollywood fantasy, the stage musical returns the material to a heightened realm.

As Nair pointed out, it is a natural fit for musical theatre - the story "has music in its bones", she said - but she has collaborators, including Dhawan, who are unlikely to turn it into a frothy confection.

The musical's composer, Vishal Bhardwaj, is an accomplished film director in his own right, part of a generation of Indian film-makers who have rethought some Bollywood conventions.

"What used to happen in Bollywood is, when the song came, the narrative stopped," Bhardwaj said. "But film-makers of my age, we started experimenting with having the story and narrative not stop, but move forward through the songs. That's what happens on Broadway, so that helped me."

He has been writing songs with lyricist Susan Birkenhead (Jelly's Last Jam) in a long gestation process with Nair and Dhawan that goes back to 2006, when the far-flung collaborators began work on the musical.

Much of the Monsoon Wedding story has been serendipitous. The film's success both in the United States and India came as a pleasant surprise to its makers. And Nair acknowledged that the notion of turning it into a musical did not originate with her.

"It was Sam Cohn's idea," she said.

Cohn, a powerful ICM agent, had offices across the street from the Paris Theatre on the upper West Side, where the film ran for months, and he made a habit of dropping in on it several times a week.

"He told me he regarded Monsoon Wedding as an anti-depressant. And one day as he was hanging up my coat at the Cafe Luxembourg, he said, 'Mira, you really should think about making Monsoon Wedding a musical.' And it was like - bing. A penny dropped."

Though it is her first work on the stage since her collegiate days working with Badal Sarkar, a radical Bengali street-theatre director in Kolkata, Nair has taken to the new medium with gusto. She is one of four producers on the show.

With a staging that aims to put the audience inside the building of a traditional Punjabi wedding tent, this Monsoon Wedding represents a return to Nair's roots in another way.

Born in the state of Odisha in India, where the local cinema had limited offerings, the first dramatic narratives she saw were not on-screen at all.

"When I was around 13 or 14, the mythological theatre would come through town - the Jatra, which means literally travelling theatre," Nair recalled. "It was bare props, a set of stairs in a school field. Whole tales from our ancient books, from the Mahabharata, the Ramayana, would be told with just three actors.

"It was this form that really enthralled me - the fact that you could take people into an amazing story with nothing except the words and the performance."

It is a long way from that bare field to a Broadway-aimed musical, let alone Hollywood film-making. But Monsoon Wedding takes up one of Nair's pet themes: continuity in the face of rupture.

As she put it: "It's really about the unbroken line of family and the rock and roll that happens within that."

NYTIMES