It really is a great rock'n'roll shriek. Craig Nicholls opens his mouth, contorts his tongue and releases a furious melodic caw. He looks and sounds like a baby pterodactyl that's fallen out of its nest –something that probably hasn't been considered endearing since the Jurassic era –yet tonight, it somehow looks like one of the coolest things on the planet.

Let's be honest, it's not as if the last couple of years have been light on strange spectacle: in recent memory, audiences have been greeted with bands dressed as clowns or mass murderers, New Yorkers masquerading as giant rabbits, bearded Scandinavians in alarming tunics and, hell, Andrew WK. Nobody's easily impressed. Yet right now, the oddest, most compelling sight on legal display is a pale young Australian with dirty-blond hair and a dog-ate-my-homework vibe, who plays a guitar and wears T-shirt and jeans. You couldn't have been waiting for The Vines if you'd tried but God, it's wonderful to be surprised.

They lope on stage and immediately play their first two British singles, the delicious sun-dried 'Factory' and the speeding-bullet punk of 'Highly Evolved'. As statements of intent go, it's somewhere between the Communist Party Manifesto and a ransom note –'these are the songs you might know, but hell, you're going to love the others just as much' –and you hand over all your attention without a second thought.

'Highly Evolved' is a telling title – the pop explosions, effortless dynamics and distilled adrenaline might bear the mark of Nirvana, but like those Japanese kids who are evolving new thumbs thanks to the age of the games console, The Vines are messing with the genes of the rock'n'roll beast. Songs like the superb yowl of 'Get Free' or liquefied bliss of 'Country Yard' might look structurally familiar, but they're popping gills and fins and wings all over the place, all those unexpected codas and hooks and solos moving things on to the next level.

Sure, the dreamy psychedelic moments could soundtrack sun-dappled cinefilm of stoned Beatles at play, but it still sounds fresh and new: bassist Patrick Matthews harmonising beautifully on 'Sun Child'; the dark guitar wrangling of 'Mary Jane' (Craig: "I thought that song would never end") and the pure commune-freakout '1969'. A mournful cover of Outkast's 'Ms Jackson' taps their Dazed And Confused summer babe vibe with style but it's their songs which prove they're capable of more than puppy love: the unhinged melodies of 'Get Free'; the loveably warped 'Drown The Baptists', a brilliant bubblegum finale of 'She's Got Something'. And all the time, while drummer Hamish Rosser is playing like a man with tentacles rather than arms and Patrick is the tall and elegant anchor, while Craig is baked from the same pale clay as Jack White, 'Pete Yorn' written curiously on his arm, playing 'Autumn Shade' with a cigarette up his nose, then putting it in his mouth and lighting it.

In the audience, Arthur Lee –frontman of seminal '60s group Love –grins broadly. It looks like he approves. Beyond the rich reinvention of it all lies that vital sense that The Vines understand the magic of The Moment, that weird, fleeting chemistry of people and songs on a stage. In other words, they're just a great rock'n'roll band. And as everyone knows, that can mean the world.