The National Theatre’s Our Ladies of Perpetual Succour is blisteringly funny to watch

Six choristers harmonise angelically. When the last note of Mendelssohn dies, they slouch into their smoking, swearing, oversexed and hard-drinking selves.

It’s a juxtaposition that director Vicky Featherstone mines brilliantly in this exuberant, blisteringly funny play, which transfers to the National following an Edinburgh premiere and tour.

The gang of convent schoolgirls from a small, Scottish seaside town descend on Edinburgh for a choir competition – and 24 hours of escapist hedonism.

A cracking ensemble plays the six girls and everyone they encounter, from lecherous men to a formidable nun.

Lee Hall, of Billy Elliot fame, adapts Alan Warner’s 1998 novel, retaining the earthy dialogue and picaresque structure – as brash, chaotic and impetuous as its protagonists.

He’s also attuned to the social commentary, with these girls doubly limited by class and gender, and painfully vivid encapsulation of what it feels like to be 17.

The group transcends their circumstances through friendship and music, with a varied set list – classical mixed with Bob Marley and Electric Light Orchestra – superbly arranged by Martine Lowe (Once) and accompanied by an onstage band.

Each spine-tingling number illuminates individuals and celebrates sisterly acceptance.

The cast is pitch-perfect: Melissa Allan’s eager cancer survivor, Frances Mayli McCann’s lippy Kylah, Caroline Deyga’s yarn-spinning Chell, Kirsty MacLaren’s hyper Manda, and Dawn Sievewright and Karen Fishwick revelatory in multiple roles, including a posh girl and tough leader with surprising hinterlands. Chloe Lamford’s set, centred on their local disco, is authentically sticky and seedy.

With Nineties nostalgia (flaming sambuccas, Doc Martens and landlines), multiple coming-of-age issues and eye-wateringly frank exchanges – sperm is “like snot, but warmer” – some elements feel undercooked, like the Catholic repression fuelling rebellion.

But the unapologetic liberation of these vital, raucous, fearless and fragile girls, if temporary, is a heavenly joy.

Rating: 4 stars