Enda Walsh had been touring Disco Pigs for two years when he was brought back down to earth with a bump in terms of pushing an audience’s expectations. Walsh’s breakout play, about a boy and a girl who create a private world for themselves, communicating in their own motor-mouthed patois as they take on the universe with devoted and self-destructive intensity, had originally starred Eileen Walsh and a young Cillian Murphy. It was the success of the show, produced by the Cork-based Corcadorca company, at the 1997 Edinburgh Festival Fringe that made it such a game-changer for everyone involved. Some, however, weren’t impressed.

“We felt like we were kings of the world,” says Walsh, “and we were in Leeds, and afterwards this guy just said, ‘Well, that was a waste of time’. It was then I realised that’s just how it is.”

Walsh is using this anecdote in an attempt to illustrate both how his approach to playwriting has changed in the last 20 years, and in relation to Ballyturk, his 2014 play which is revived in a new production which opens at the Tron Theatre, Glasgow this weekend. Originally seen in Galway before travelling to Dublin, London and New York, this will be the first revival of the play since the original production.

Set in a solitary room where two men exchange increasingly ridiculous chat, Ballyturk is nevertheless far less frenetic than much of Walsh’s post-Disco Pigs work such as The New Electric Ballroom and The Walworth Farce.

“You see these two guys who we think are idiots,” says Walsh. “They’re having this mad conversation about bunnies, and are acting out all these scenarios about people in the neighbourhood. They’ve never seen a fly or a flower, and they don’t know how to deal with them, and then something happens, and out of all this madness it very quickly becomes a meditation on living.”

The roots of the play were two-fold, the first when he was directing his play Misterman with Cillian Murphy, with another actor, Mikel Murfi, in the room.

“Mikel was down as fight director,” says Walsh, “which was basically about Cillian beating the s*** out of himself, but really I needed Mikel around for confidence. Watching the two of them, there was an empathy there, with real juxtaposing energies playing between them. Then they asked me if I’d write something for them, and that became Ballyturk.”

Another influence was Walsh’s then six-year-old daughter. “We were out one day, and she asked do old people die,” says Walsh, “and I said, yeah, but they don’t think about it, they just get on with things and eat and have friends or whatever. That got me thinking that I should really write a piece about innocence, and have these two people who have no knowledge of death, but they hear about it, and see how that affects them as their innocence implodes.”

Walsh is currently in the midst of directing a production of Bela Bartok’s Bluebeard’s Castle for Irish National Opera. The most recent work by Walsh to be seen in Scotland was The Last Hotel, another opera which formed part of Edinburgh International Festival. Both illustrate the expansiveness of Walsh’s canon, which also includes the hit musical, Once, and Lazarus, created with the late David Bowie. All of these have seen Walsh explore form in ways that create worlds that initially look familiar before lurching off into something less recognisable. Such is the case with Ballyturk.

“The big breakthrough for me was wanting to write something that the audience can pick up, and each member of the audience has their own version of what happened. The audience can go in and ask, we’ll, where are we? Then at the end they’ll hopefully still be asking questions.

“It’s quite liberating, doing that. Watching the play, you can feel the audience after about fifteen minutes go, okay, this is how t’s going to be, and they put the intellect out of the way and go with the ridiculousness of it.”

A couple of years ago Walsh wrote a piece which has yet to see the light of day, but which had a solo dancer perform in the middle of the play, with not a word spoken. This is a long way from the breathless tumble of words in Disco Pigs.

“I do like words,” says Walsh, “but I’m always a little bit embarrassed by them. I’ve been directing my own work for the last seven years now, and that’s had an effect on how I write. That’s about leaving space, and realising you can tell a story visually. Every seven years or so I feel something change in how I write. I can’t put my finger on what happens, but it’s there alright. I suppose it’s just about how you tell stories. We have all this tone and atmosphere that we can create, but it’s about finding something to hang on that.”

In this sense, Walsh has been doing his artistic growing up in public.

“I think I’m a writer of a certain age whose early plays are all about words,” he says. “Then you start writing really well-formed plays, but then you realise you’re not into that, so you find other ways of telling a story.”

In Ballyturk, this comes through a third character who intrudes on the two men’s private world.

“The person at the door is a huge figure in Irish theatre,” says Walsh. “They change the destiny of the play.”

Walsh talks about Sean O’Casey’s similarly form-busting play, The Silver Tassie.

“In the first act that feels like a piece of naturalism,’ says Walsh, ‘then the second act goes completely crazy.”

In Ballyturk, at least, this puts a lot of demands on the three actors performing it.

“It’s an actors play,” says Walsh. “It really puts actors through it. Even Stephen Rea when he did it would come off absolutely shattered. It demands a lot of physical effort. I’ve always liked that, asking actors to be superhuman and exhaust themselves so people can find a clarity beneath the insanity.”

How the audience discover that clarity for themselves in Ballyturk remains to be seen.

“I hope after the show people will get on the bus or be in the bar and go, okay, what did we actually just see?” says Walsh. “But like with Disco Pigs, there will be people who will look at it and go how dare you? And that’s okay.”

Ballyturk, Tron Theatre, Glasgow, October 4-20.

www.tron.co.uk