In Lee Hall’s play with songs, six Catholic schoolgirls sing like angels but swear, drink and shag like there’s no tomorrow.

Taking to the stage, six teenage schoolgirls in kilts, school jumpers and Doc Martens, line up and deliver a sublime six-part version of the trio Lift Thine Eyes from Mendelssohn’s Elijah. The next minute they are talking dirty about submariners drowning in their own spunk after too long at sea, punctuating their exuberant, potty-mouthed chat with more swear words than the proverbial sailor.

The cast of Our Ladies of Perpectual Succour. Photo by Manuel Harlan

Armed with soft drink bottles and thermos flasks laced with alcohol, the girls from the small Scottish seaside town of Oban are off to Edinburgh to represent their Catholic school – Our Ladies of Perpetual Succour (or “the Virgin Megastore” as they dub it) – in a choral competition. However, they’re more interested in “going mental” and getting drunk, getting laid and then getting back to the scuzzy local nightclub The Mantrap in time for the final slow dances.

Co-produced by the National Theatre of Scotland and Live Theatre, Our Ladies of Perpetual Succour follows the girls over the course of 24 hours as they run amok through Edinburgh. It is gob-smackingly rude in a cheery, joyous kind of way, hilariously funny and yet very touching as they learn more about each other and themselves.

Superbly performed by a cast of Scottish actors – Caroline Deyga, Karen Fishwick, Joanne McGuinness, Kirsty MacLaren, Frances Mayli McCann and Dawn Sievewright – the play has been creating a big buzz at the Melbourne Festival where it opened to rave reviews and plays until October 22.

Our Ladies of Perpetual Succour was adapted by British playwright Lee Hall from Alan Warner’s 1998 novel The Sopranos. Hall, whose credits include the book for the musical Billy Elliot, read Warner’s novel shortly after it was published and fell in love with it. “What’s remarkable about the book is that Alan captures the amazing life force of working-class teenage girls on the rampage without any sense of censoriousness,” wrote Hall in a piece for The Guardian last year. “These were the girls who are constantly pilloried by the purveyors of moral panic. Condemned by all sides because they are poor, seemingly ‘uncultured’, common, working class, yet here they were heroes of their own story. It seemed perfect material for the stage.”

In a note in the theatre programme, Hall says he loved the way Warner “smashed” the sacred and the profane together, adding: “The play is about very ordinary acts of resistance and how that resistance transfigures us and affords us transcendence from the mire of our lives.” Hall discussed the idea of a stage version with Vicky Featherstone, the founding Artistic Director of the National Theatre of Scotland (2005 – 2012), when they happened to meet at a theatre awards ceremony around eight years ago. It took several years to acquire the stage rights, but finally Featherstone (now Artistic Director of London’s Royal Court Theatre) directed the premiere in Edinburgh last August. The show has since toured around the UK, to America, and now to Melbourne, arriving directly from a two-month season at London’s National Theatre.

Associate Director Debbie Hannan has been with the production since it began touring around five months ago – and she relates to it big time. “It was my favourite novel,” she says in her lovely Scottish brogue. “I was a Catholic schoolgirl in the 1990s so I remember when I read it [being struck by] the pinpoint accuracy of it. I was like, ‘yes! This is my life’ – even if it was more exciting than my life.”

Hannan believes that the inspiring use of the 15 musical numbers in the play is a key element in its success. Backed a female trio, the performers sing Mendelssohn, Bartók, Bach and Handel as well as a number of ELO songs including Mr Blue Sky, Don’t Bring Me Down and Sweet Talkin’ Woman. “I think the songs do a lot of work for it,” she says. “I think there’s a simplistic notion that these working class women who want to get laid and have a good time couldn’t possibly sing a beautiful Bartok three-part harmony – but actually all those things exist together. So it’s quite intriguing to just present that really boldly. They can swear and smoke and produce music of great beauty and be 17 and terribly flawed and still be heroes.”

Hannan says that Featherstone cast the net extremely wide when auditioning for the show with musical arranger Martin Lowe, whose numerous credits include the West End productions of War Horse, Les Misérables and the new Harry Potter and the Cursed Child, as well as Once in the West End and on Broadway. “There are full length rock ‘n’ roll numbers and these delicate hymns, so it’s really challenging. They had to find people who could handle these complex harmonies as well as really big, meaty acting roles,” says Hannan.

Not only do the six actors play the schoolgirls, each with a distinctly different personality, but all the other people that they come into contact with – around 50 characters in total. Chatting about the rehearsal process, Caroline Deyga and Frances Mayli McCann say that the cast had a genuine input into the creation of the key roles. “We had five weeks rehearsal and the script changed and developed every single day. It was nothing like I’d been in before. It was a really exciting process,” says McCann.

“Sometimes over a lunch time, it would change,” adds Degya. “You’d come back and a whole new scene would be presented to you, based on what we had given them [that morning]. Towards the end of rehearsals, heading into previews, Lee would actually say to us, ‘well what do you think she would say there?’ That would take me aback because Lee is such an esteemed writer but he is so generous and I think it did reach a point where the characters were so inside us that we embodied them.”

Asked about the audience reaction to the swearing, not to mention some hysterically crass lines, Hannan says that “it completely depends where it is. The word ‘cunt’ is in the show. It doesn’t have the same weight [in Scotland] but when we did it in America it was like a bomb going off. My Mum thought it was far too sweary but generally people are OK with it.”

McCann, who also had a Catholic education, admits she gave her parents a heads-up warning as to what to expect. “They absolutely loved it, though my Dad said afterwards: ‘OK, we’re going to confession first thing in the morning!’” she says, laughing.

“I don’t think any of us knew what would happen here,” says Deyga. “But, my goodness, Australians are up for it. It’s been brilliant!”

Our Ladies of Perpetual Succour plays at the Fairfax Studio Arts Centre Melbourne until October 22