DRESSED in vibrant colours the good- looking, smiling and well-tanned Australian quintet, aptly named Hi-5, appear every bit the pop band they are.

They sing live, dance and play their own instruments, boast sold-out venues whenever they tour and have an international fan-base that is spread over 63 countries.

But it’s not hysterical teenage kids who are captivated by them - it’s pre-school children. After the Teletubbies and the Tweenies, Hi-5 are the latest phenomenon to take children’s television by storm.

Currently the top-rated children’s programme on five - they knocked Bob the Builder off the top spot - Hi-5 is a bright, lively and funny singing show designed specifically by educational experts for the media-literate children of today.

It’s popularity has been such that now the band of young 20-somethings who present it are embarking on a worldwide tour with Hi-5 Alive, which makes its way to the Festival Theatre next week.

So what is it that’s made Hi5 so popular? "It’s really like a pop group for kids," explains 24 year-old presenter Nathan Foley who joined the band at the age of 18. "We are a pop group but with educational values and we push this as much as possible. We take on a big brother or sister role as opposed to a parental role and just try to have fun."

With a vibrant mix of stories, investigation, imagination and adventure, Foley describes the tour as an all-singing variety show just for the young.

The educational aspect of what Foley terms "S Club 7 or Steps with education", is achieved through an impressive production team.

"We have child advisors who work with the show," explains Foley, "and our writers have children of their own and have been teachers before this. They write the lyrics to the songs and put together the individual learning segments."

The live show follows the format of its TV counterpart, beginning with a themed song of the week and dance routine. Then, each presenter performs a solo singing segment designed specifically to teach and encourage children to join in. To finish, there is another group song performance.

With this mix of learning and entertainment Hi-5 have enjoyed international success since launching in 1999. Their first album Boom, Boom Beat went Platinum in Australia, and was released by Sony in the UK last year - move over S Club Juniors.

The stars of Hi-5 are Foley and his co-presenters Tim Harding, Kellie Hoggart, Kathleen De Leon and Charli Robinson. They are joined on stage by Chatterbox and Jup Jup, cheeky little creatures who live in cardboard boxes.

"There is nothing like us on TV," says Foley frankly. "We are fresh and exciting for the kids as our music is Top 40 quality but with kid lyrics and that educational side to it. They just love it."

But how much do they really love it? After a brief pause, Foley answers: "Some audiences are more conservative than others. In Singapore for example we get parents and kids coming up to us on the street but they are more conservative in the show. Australian audiences are great fun - they jump up and down and really get into it. And the British audiences get really into it. The shows we have already played here felt like we are at a soccer match, it’s amazing. As far as we are concerned the louder they are the better."

And although their fan-base may be predominantly young children, Foley says it’s the parents who are the worst. "We get mobbed by parents," he laughs. "The kids get shy and it’s the parents who mob. They are the driving force who go wild at our shows!"

• Festival Theatre, Nicolson Street, Tuesday-Thursday, (Tue 1pm, 3.30 & 6pm, Wed 1pm & 3.30, Thu 10.30am & 1pm), 8-15, 0131-529 6000