Damien Leith returns to the stage with Irish play The Parting Glass

When the show premiered in Adelaide, however, plenty were surprised to find themselves sitting down instead to watch a fully-fledged play.

"The first night there was definitely a lot of people who'd come to the shows in the past and that was the feedback: 'I didn't think that was going to happen'," says Leith. "I suppose they were going in thinking they'd be hearing Irish music but didn't expect there was going to be a play as well."

The Parting Glass isn't so much a departure for the Australian Idol winner as it is a return. "The thing that got me into music in the first place was the fact that I used to love writing plays. I loved drama as a kid and wrote loads of plays and put them on, and then from plays I went into musicals, and then musicals got me into singing. I've always loved drama, loved acting, and definitely loved writing. I suppose it was a long time coming, really."

When the show debuted at the Adelaide Cabaret Festival it had been years since he'd done any acting, and admits that it was a "nerve-wracking" prospect to switch back into that mode.

"(As a singer) you can go with the audience, you can respond to how people are reacting to what you're singing, so you're not bound by a script in any way. But definitely with the drama side you've got to deliver the story and get it across. There's a script to be delivered."

Not that the show is free of music. Leith plays both a father and son meeting up in an Irish bar and over a drink the various secrets they've been holding onto begin to find air. Stop by any similar pub in Ireland and there'll likely be a band in a corner serving up traditional songs, so the play is broken up by standards performed by Leith and a full backing outfit.

"I tried to make it authentic as to what will actually happen in a pub in Ireland on a Sunday afternoon when a group of lads will come in with their guitar and fiddle and start playing."

The songs are the sorts of standards Leith has always loved, he says: the number that gives the play its title, Raglan Road, even Danny Boy. The instruments are traditional, too, from the fiddle and tin whistle to the bodhran (Irish drum) and Uilleann pipes. The playlist also gives Leith a chance to focus on harmonies, another departure from form for the singer. "I don't normally do a lot of harmonies in my own solo stuff. There are very strong, deep harmonies in this. Those celtic four or five-piece harmonies feature a lot in this as well."

While the setting is true to life, its characters and their dramas aren't based on specific people but are amalgams of the many stories he heard from regulars during his own days working in bars. "They're definitely based on characters that I've come across over the years," he says.

"I suppose there's a little bit of me in there. Not in the story, which has nothing to do with me at all. I suppose the only similarity is that the son has just come back to Ireland from Australia, so I get to talk about some of my Australian experiences in the show as well. Other than that it's just real people I've met over the years."

The Adelaide run may have been a surprise for the fans, but it was a welcome one. "I was so happy with the response," he says. "Especially from people who said it wasn't what they expected but they loved it." He's since expanded the show and fleshed out its central characters, and is currently touring it around the country.

It's likely just the start of something, too. Leith has quietly been writing more plays "straight up with no music" and recently edited three that are calling out for some kind of production.

"One of them's a comedy, the other is very much a tragedy, and the third is somewhere in between. I'd love at some point to get them out, but this is a nice place to start."

The Parting Glass plays two shows at Chapel Off Chapel on February 21. chapeloffchapel.com.au