But that is exactly what Alex Rathgeber has done, scoring a lead role in the hit musical.

Rathgeber will play the role of Greg Connell, the partner of lead character Peter Allen, played by Todd McKenney.

Scoring the role capped off a huge year for Rathgeber, which included tours of New Zealand and Korea as part of The Rocky Horror Show, and working with Geoffrey Rush.

He said he was looking forward to performing back home opposite McKenney.

"To be able to perform in Australia in a home-grown show is really exciting," he said.

"McKenney got amazing reviews when he played the role 12 years ago ? he was dynamite back then. He's had so much time to live with the role and it is brilliant to play opposite him."

Rathgeber began rehearsals last week.

"We only have three weeks of rehearsals which is unusually short," he said. "It's a fairly long day, from 10am to 6pm with not much of a lunch break. It's a pretty intense few weeks. It's a really amazing show.

"Peter Allen wrote so many well-known songs such as I Still Call Australia Home, I Go To Rio and I Honestly Love You.

"It's got lots of entertainment, pizazz, excitement and great big dances.

"It goes through his life and is full of flashbacks to his childhood, sort of a concert from the grave ? like he has come back to tell his life story."

Rathgeber said performing in The Rocky Horror Show early last year was a highlight.

"We rehearsed in Sydney and toured Korea and New Zealand," he said.

"We had the writer, Richard O'Brien, in the show with us and that was a huge thrill.

"He's a fantastic guy. It was a huge buzz. The atmosphere in the theatre was just insane. I've never performed in anything like that before."

Rathgeber had just finished the show when he was offered the role of Greg in The Boy From Oz.

"My agent called and asked if I'd be interested and I just jumped at it," he said. "It was perfect timing."

The next few months will be busy for Rathgeber.

After the Melbourne leg of The Boy From Oz wraps, he will play a concert at Malvern's Ardrie Park on February 12 with Rhonda Burchmore and Matt Hetherington.

The Boy From Oz will play at the State Theatre at the Arts Centre in Melbourne from January 5 to 16 and from February 9 to 13.