Jill Hennessy has an identical twin sister named Jacqueline.

They were known as Jack and Jill as little girls, and that was the name they used when they sang together. (Jill Hennessy says of being a twin, "It's great to get attention, but you sort of want to run away from it too. So you experience this weird dichotomy.")

Jacqueline Hennessy is a broadcaster and an award-winning journalist, and then there's the singing. "We would always make up songs and sing, from the age of three or four," Jill says.

"We just loved doing it. I didn't think of it in terms of a livelihood. In high school, I thought I'd go into fine arts, languages, perhaps writing -- but I didn't think of acting or music even as an option."

So what was the arts influence? Probably their parents, says the actress, who both love music and were completely encouraging of their daughters.

"They gave us so much confidence and support to try anything. They never dissuaded us from any endeavour, which was pretty gutsy on their part. I think they have great taste in music and always played great stuff for us."

According to Jill Hennessy, their mother told the girls about going to see Ian and Sylvia (Tyson) in concert when she was pregnant with them.

"She always told us, 'It was great. You guys started kicking as soon as the music started.'

"I guess we had an early folk influence."