Director John Tiffany on how Tennessee Williams changed his life

John Tiffany studied theatre at Glasgow University in the 1990s. Picture: Colin McConnell/Getty Images

This afternoon will be a treat, says John Tiffany. Not only will I see his actors rehearsing The Glass Menagerie – a hit on Broadway, and now bound for the Edinburgh International Festival – I’ll hear them read from unseen Tennessee Williams, two scenes unearthed in the Harvard archive, written before the play, when he planned The Glass Menagerie as a film.

They won’t be in the production – this is background, and, to judge by Tiffany’s expression, pure joy. The company, from American Repertory Theater, slip almost seamlessly from them into the play’s dinner scene, actress Cherry Jones doing a flawless Amanda Wingfield, exuding a kind of desperate charm. “Hillary Clinton could do with a bit of Amanda, couldn’t she?” Tiffany quips. “That southern hospitality.”

He has spent the past week juggling Menagerie rehearsals with the final preparations for Harry Potter And The Cursed Child, which has just opened on the West End. It’s the culmination of two years’ work, a mammoth two-parter with a cast of 43 which he has shaped along with JK Rowling and writer Jack Thorne. It’s sold out until next spring.

If he’s nervous – the first reviews are due the day after we meet – he’s showing none of it. (In the event, they’re very good; see opposite) Nor does he seem in the least bit tired. Tiffany fizzes with suppressed energy, whether he’s putting actors through their paces or devouring a box of salad. He fidgets constantly, as if there’s always more energy than his body can contain.

At 44, he’s regarded as one of the world’s hottest directors. If it was National Theatre of Scotland’s multi-award-winning Black Watch which first brought him to international attention, he held on to it with a diverse range of productions: Alan Cumming’s one-man Macbeth, which went to Broadway, Scandi vampire tale Let The Right One In, which had a long run the West End, and the musical Once, which won eight Tony Awards.

Tennessee Williams’ 1944 classic, though, feels like a wild card, until one learns he fell in love with it while studying theatre at Glasgow University in the early 1990s, when he was given a copy by his tutor, Alasdair Cameron. “He said, ‘This play will change your life,’ and it did,” he says. In his preface, Williams sets out his philosophy for the stage – what he calls “plastic theatre” – which is also Tiffany’s own. “Williams says theatre isn’t real: ‘I don’t want realism, I want magic,’ which I realise is absolutely what inspired me. Williams says the death of American theatre is the ice cubes in the glass. Who needs ice cubes in a glass in theatre?” He chuckles. “Who needs a glass?”

Tiffany came to Glasgow from his home in Yorkshire to study medicine. “I come from a community where you never do art for a job, it’s always a hobby.” He had an inclination for the stage, playing the lead in Oliver! at Huddersfield Town Hall at the age of 10, but was put off by being made to sit through Shakespeare as a teenager. “I didn’t understand a word of what anyone was saying. Even now, I really struggle with Henry V. At 13, I thought, I’m too thick to do theatre,” he breaks into another big laugh, “I’ll be a doctor instead!”

But fate took a hand, and he arrived in Glasgow just in time for the city’s stint as European City of Culture. He remembers the precise moment in Robert Lepage’s Tectonic Plates when he decided to ditch Biology in favour of Classics and Theatre Studies. “He had a pool on the stage, we were in a library in Venice, so there were all these books stacked at the side of the pool. The next location we had to go to was New York, and all that happened was he turned the lights on behind the books and you had a silhouette of the Manhattan skyline reflected in the Hudson river. Suddenly, I thought, ‘Ahh! We literally have no limits, our only boundaries are whatever we create ourselves. I want to do that!’

“My mum and dad were terrified for me.” He pauses. “My mum came to the opening of Once on Broadway, and she’s coming to the opening of Harry Potter – she’s not complaining any more!”

By 1995, he was assistant director at the Traverse, which was then nurturing young writers like the Davids – Harrower and Greig, Nicola McCartney, Zinnie Harris. Tiffany’s directoral debut was Stephen Greenhorn’s hit Passing Places. He would also direct Siobhan Redmond in Liz Lochhead’s Perfect Days and Gregory Burke’s storming debut, Gagarin Way.

Along with Neil Murray, David Greig and others “in various cupboards, kitchens, pubs, train journeys”, he helped “hatch” the National Theatre of Scotland. Old friend Vicky Featherstone became its first artistic director and he joined as associate director in charge of new work. In his work for NTS, most notably Black Watch, he crystallised his interpretation of Tennessee Williams’ plastic theatre, a heightened physicality, achieved by working with Steven Hoggett, a founder of physical theatre company Frantic Assembly, whom he has known since they were both 15.

The early years of NTS were “a truly extraordinary moment”. Tiffany found himself socialising with A-listers and rock stars. But he says the moment that resonates most with him from his NTS years is one no celebrity ever saw. Hunter was a “Transform” outreach project in Thurso, featuring a cast of nearly 200 from schools and community organisations. A promenade production he co-directed with Hoggett, he said at the time it was the most ambitious thing he’d ever done. “And that was true,” he laughs. “Until Harry Potter!”

He continues: “Me and Steven still talk about Hunter as being our proudest moment in everything we’ve done so far. We went into this community saying, ‘We’re going to transform lives, kids are going to go to drama school,’ and all that happened. However, what we weren’t prepared for was that the people who were going to be most transformed were us. I realised that work like this can actually be the most experimental. The audience was looking around them in the town, they didn’t know what was part of the show and what wasn’t. You look at the world in a different way. I love that.”

Does he worry about NTS now, with the departure of Featherstone’s successor, Laurie Sansom, after just three years, and the loss of stalwarts Neil Murray and Graham McLaren to run the Abbey Theatre in Dublin? “It depends who they appoint,” he says, looking, for a moment, very serious. “And get that small-scale touring back out. That’s the most important tour to do. You’re taking amazing work to places that don’t get theatre. It’s certainly as important as me taking Macbeth to Broadway, you can’t have one without the other in Scotland.”

With Harry Potter up and running, he says he hopes to take life at a slower pace. He has bought a bungalow on the West Yorkshire coast, near his family. He and his partner, David, a theatre producer from Melbourne, will divide their time between there and London. “If you’d have said to me ten years ago, ‘Where will you be living in ten years’ time?’ I’d have said New York, I would not have said between London and a tiny little bungalow where I’ve had to pull the carpet up in the bathroom because the cistern leaked and there’s pink anaglypta in one of the bedrooms.” He giggles.

“I definitely want to slow down now and start thinking about the world in different ways. I’m getting very angry – at everything in the world at the moment, who isn’t? But specifically about how art and education has just been demolished.” Schools in England, he says, are now judged on five GCSE subjects, none of them arts. “I mean, have we not learned anything? I’m starting to get quite angry about it, and I think I understand how to talk about it. So I think I might start to shout about it.” Bungalow or not, we haven’t heard the last of John Tiffany.

• The Glass Menagerie, King’s Theatre, 7-21 August. www.eif.org.uk