One man, a monkey and two bodies attached to some oversized papier-mâché heads (called Shona and Betty) dangle precariously inside a hot-air balloon. An unconventional musical collective strum guitars and bang on toy tambourines, wooden blocks and maracas (which look as if they have come from the Early Learning Centre). They’re attempting to play Finn Bikkjen, a sunny pop melody that recalls Simon and Garfunkel at their most chilled out. But it’s hard to keep a tune while trying to keep a wicker basket aloft.

“KRRRRRRRRRRRRSSSSSSSSSSS,” goes the guttural engine in the middle of a particularly beautiful middle eight. “KRRRRRRRRRRRRRSSSSSSS,” it goes again. A mood killer it might be, but Shona, Betty and the others soldier on, occasionally cracking up at the absurdity of the noise and the entire situation.

Despite the Fellini-like nature of the scene, we’re not in 1950s Rome. Instead we’re in Norway, witnessing electropop’s brightest lights, Casiokids, make their theatrical entrance to the Hove Festival.

Who are they? A bunch of misfit Norwegian musicians rubbing delicate folk melodicism into a bouncy, 1980s pop palette, the Kids’ charming spirit of mischief is the perfect fit for the carefree vibe of Hove.

Located on the idyllic island of Tromøy, Hovefestivalen (as the locals call it) is a world away from the muddy realities of a British festival. Instead of the sight of a cack-handedly erected tent on a slowly sinking mud pit, there are kilometres of untouched, Eden-worthy scenery. And rather than grim-faced revellers walking around the site like disgruntled characters in a Ken Loach film, everyone looks like sun-kissed Abercrombie & Fitch models.

Casiokids’ hot-air balloon entrance works as both an extravagant homecoming and a way of encompassing the childlike spirit of the band. “Playing in the balloon was beautiful, so peaceful . . ,” muses the singer-guitarist Fredrick Øgreid Vogsborg later in the day. “But then the screech of the engine spoilt it. It ended up sounding like Simon and Garfunkel crossed with a death-metal concert.”

Øgreid Vogsborg is the contemplative member of the Casio collective, whose bookmark-thin features make him the “looker” of the band. Casiokids’ music — flitting between a post-punk chug, dancefloor banging and Beach Boys harmonics with ADD-like glee — could only be made by five incredibly different individuals.

And so it is. As well as Øgreid Vogsborg, there are the fanciful keyboardist Omar N’Dur and the bassist Kjetil Bjøreid Aabø, whose intense blue eyes and deep voice belie a sense of camp that shows itself in a huge exclamation mark tattoo on his forearm. The bearded singer-guitarist Ketli Kinden Endresen and the sleepy-eyed drummer Jøachim Trana Amundsen look as if they have escaped life as Neil Young’s roadies.

On stage a lo-fi carnival spirit pervades. Songs such as the bright, 1960s-flecked pop of Grønt Lys i Alle Ledd (the only single in Britain to be sung solely in Norwegian) and the dirty funk of Gomurmamma float through the air like handfuls of glitter. During the performance they are flanked by Shona, Betty, some coloured balloons and a backdrop of rotating, pop-art animation, including, memorably, a giraffe with a large 99 ice cream sticking out of its head.

“This is our 110th live show this year and every one of them is special,” explains Bjø- reid Aabø, “We love the Flaming Lips on-stage get up, but our vibe is more DIY, like doing videos with life-sized puppets.” Exciting as it is, Bjøreid Aabø says that the practical aspects of this type of show aren’t always simple: “We had a roadie whose sole job was to take off the heads and she forgot,and I was trapped and couldn’t sing! So we ended up freestyling, but I couldn’t breathe that well.”

It is no surprise to learn that the band’s earliest shows began more as performance art than gigs. “It was more like an art collective than a band,” Kinden Endresen agrees. “There were 12 of us and we wanted to keep things really loose, so we jammed while our animators did wacky improvisations.”

Going along with their art-minded ethos the band eschewed the normal broom-cupboard-sized venues for art spaces and kindergartens, where they played a 12-date tour. “The kids were so ... honest! It was scary,” Bjøreid Aabø says.

The band have released a series of singles but are holding off releasing a full album until 2010, a decision that is born out of a fatalism about the industry. “People don’t buy albums any more,” says Øgreid Vogsborg. “It seems to me that one-off singles are more appropriate. But when we do, it’s definitely going to have some sort of concept running through it.”

The serially inventive Casiokids releasing a “concept” album? You can bet it’s going to be something very special indeed.

Casiokids play Bestival, Isle of Wight, on Saturday and tour the UK Oct 1-14. Their single En Vill Hest/Min Siste Dag is out in November on Moshi Moshi

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