ROCK star’s reputation for outrageous behavior and wildness doesn’t work for Newton Faulkner.

The multi-million selling singer-songwriter of hits such as Dream Catch Me isn’t about to be caught trashing a hotel room anytime soon.

In fact, he’d be the last man to even leave a towel on the hotel bathroom floor, never mind toss a TV out the window.

“I haven’t done that yet,” he says, grinning, in his dressing room in Birmingham’s New Theatre.

“No, I tend to tidy up a hotel before I leave. I guess I don’t really say the point of being a d*** all the time.”

He reflects; “And I’m lucky, I’ve been surrounded by family so much.

“My sister is my manager and my brother plays in the band with me. If I show the hint of ego it gets stamped on. And that’s the way I want it.

“It’s the same with the director of this show; I said from the start not to go easy on me. I want to be good at this. A new skill set will go along way.”

The ‘show’ Newton refers to is his new project. Newton stars in in American Idiot, the post 9-11-themed musical based on the hugely successful album by American pop-punk outfit Green Day.

It’s a high-energy Tony Award winner that really hits home.

Yet, he agrees it’s rare, in fact non-existent, for a performer at the peak of his/her powers to choose to join touring theatre, a world of fragile egos and chipped, stained sinks.

Musical theatre has long been the reinvention studio of one-time pop stars, a second chance saloon for the likes of Jason Donovan, Marti Pellow and the boys from Blue.

Newton, whose first album, Hand Built By Robots, topped the charts in 2007, deposing Amy Winehouse, explains why he agreed to play the part of Johnny, the central character in the show.

“It was a strange how it all came about,” he says in laid-back voice. “You see, I felt my live career has been more stable than it’s ever been - I do tours loads of people come – but when I got to thirty, I was thinking ‘Is this it? Have I done everything I wanted to do?’

“And I realised there was a whole bunch of stuff I’d love to try and so I began talking to acting agents.

“They all told me exactly the same thing; ‘You can’t walk into TV without any real experience and credentials.’ And all of them suggested musicals.”

An incredible act of serendipity came about.

“Just at this time, Lucas (Rush, who stars as St Jimmy in American Idiot) got in touch and he said ‘We’re looking for someone to play Johnny in the show. Would you be interested?’

“It was perfect timing. And what was amazing was he and I had been in a Green Day covers band together when we were about twelve.

“So I couldn’t say no, could I? So much stuff was leaning in this direction.”

Not really. American Idiot, the story of three boyhood friends, each searching for meaning in a post 9-11 world, features hit songs such as Boulevard of Broken Dreams, 21 Guns and Wake Me Up When September Ends.

It’s not a jukebox show, the production values and imagery are too powerful, although the narrative is slight.

Sam Newton Battenberg Faulkner is not an acting virgin. He attended the Italia Conti stage school as a boy and went on to appear in three plays with the Royal Shakespeare Company.

That said, he’s far from being an accomplished stage actor.

“When I do my own show, the end of the line is me. If you get it wrong, the only person to blame is yourself.

“But with this, you realise there are so many other people involved, who you can let down, you’re part of a team. And just before the first show, this all hit me.”

He’s been working hard. Johnny begins a slide into drugs haze, yet still has to sing in tune.

“I had to perform it bad enough to be believable, but good enough to make a mark.”

There’s little doubt Newton will make a mark in acting. Casting directors are already hovering.

His distinctive look – he’s had the trademark dreadlocks since he was sixteen – wouldn’t be an impairment to acting success. But you admit you don’t see him as Billy Flynn in Chicago?

“No,” he says, grinning. “I’m a little bit limited by how I sing, and how I look. But I reckon I’ve got a ‘thing’ and if producers want a guy with long straight ginger hair then I’m that guy.”

There is a problem associated with touring however. Newton has a five year-old son with his ex-girlfriend.

“The little dude lives in North London and he’s so cool. But it is hard being away from him though. I was on tour before this show started, and now I’m off again. But when this is finished I’ll see a lot of him.

“Recently, he asked his mum if he could ring me, for the first time, and that was surprisingly touching. He just wanted to talk to me about a superhero cartoon and he was so excited. But I’ll be talking to him on Skype a lot.”

What emerges from a chat with Newton Faulkner is he’s far from the typical rock star. He’s soft-spoken, indulgent and considerate.

“It will be great to look back and see what I’ve done,” he says of this show.

That will include going into the West End with the show. And having to wear sub-standard underpants on stage every night when his druggie character strips off is a small price to pay.

“It is,” he says, laughing. “And when you get standing ovations each night you realise you’re on the right track.”

• American Idiot, the King’s Theatre, May 31 – June 4.