My sense of what a music festival is comes from being a teenager at psy-trance and breakcore raves, and hinges around the idea of being lost for days in a strange, depraved new universe. For a long time, to me a festival was a place where the normal rules of society didn’t apply – the only people your parents’ age were wearing fairy hats and selling magic mushrooms.

But these days, the festival industry is booming, and there’s all kinds of events to choose from – at many of them, you don’t even need to reduce yourself to eating dry Pot Noodles in a soggy tent, or bump into topless men behind the Portaloos dancing to the throb of a petrol-powered generator. Flow Festival in Finland’s capital city Helsinki is worlds away, a pristine enclosure filled with beautifully dressed Scandinavians, champagne bars, contemporary art installations and coke-can sized beers that cost seven euros.

City festivals, when you turn up in the afternoon and leave in the early morning, are a very different kettle of fish than the ones where you’re enveloped in the festival environment for at least 72 hours. Of this particular type, though, Flow is a superlative example. It is cutting edge in a lot of ways, from the sustainable energy ethos and entire strip of delicious vegan food stalls to the looming post-industrial beauty of the site: as you enter, you’re confronted with giant chimneys and spherical structures that gleam in the silver Nordic light. It’s a far cry from Winchester Bowl. Most important, though, is the line-up, and it would be hard to find a better-curated mix of envelope-pushing pop, futurist techno-soul, ambient immersion and defiantly diverse music from all over the world.

On the first afternoon, we kicked off with some homegrown Finnish music, of which there was plenty to consume. The lithe, serious Jaakko Eino Kalevi bashed his keyboard in a set of supple, incredibly 80s sounding synth pop that got a great reaction from the locals. Next, the contrasting personality of Stormzy brought the sound of the UK with a confident set of lairy grime – it was kind of strange hearing Eski beats in such a faraway place, among the polite and fashionable Finns, but the energy of the Wicked Skengman’s bars was by no means lost in translation.

Iggy Pop, on the main stage soon after, was a phenomenon, wriggling in his loose, lizard skin, projected onto screens 50 feet high, with an energy that seems to have barely waned since the Stooges’ sado-masochistic 70s shows. We drifted into The Other Sound for William Basinski, where somnolent figures slumped on the floor in the purple smoke while the composer’s disintegrating tape loops spun the room in spirals of sublimity. The first night’s highlight has to be Ata Kak, a Ghanaian-Canadian vocalist and producer whose career has been revived by the DJ/blog, Awesome Tapes From Africa. Ata Kak’s awesome tape was dug up ten years ago, an electronic highlife oddity. He may be considerably greyer now, but he performed, grinning, at midnight in the Bright Balloon ‘360 stage, where he was surrounded from all angles by eager, clapping people. He rapped through the original crackly, house-tinged singalong nonsense with gleeful energy, and it was surreal and beautiful to hear them in a more high fidelity finish.

In terms of more classic dance music, the highlight of Friday was The Black Madonna, who seems full of the adulation that she’s deservedly getting in spades right now. The barely-announced appearance of Vancouver’s next big thing, the Sex Tags Mania-affiliated Jayda G, at the closing hours of the tiny Champage Bar was a wonderful surprise too, and sweating out in a rammed little tent with drag queens vogueing on the bar sealed the deal – this is a decent fucking festival.

The next day – after enjoying the pride of Finland, the finest gin and tonic in the world, according to those who know about such things – we hit the tube again to get another dose of the festival. We couldn’t miss Lil Tony, a DJ, club owner and linchpin of the Helsinki club scene. His deep and heady set of underground house and techno in the atmospheric, lanterned garden where Resident Advisor had their stage set me in the mood for the evening. With so much to choose from in every slot, it was tricky choosing where to be, but Jeff Mills was a dead cert and he didn’t disappoint, as longtime legends can. His set built steadily into a firestorm of synth-flamed techno malice, a truly visceral experience.

I’ll come clean; by Sunday, we were having so much fun that the day is a bit of a blur and we missed the likes of ANOHNI, New Order, Sia, Anderson.Paak and many others. Honestly, the line-up here was pretty much unbeatable.

Our first stop on Sunday was Ian William Craig in the early evening, which perhaps was the wrong time for such digitally dislocated choral ambience, but nevertheless, he makes truly beautiful music. After John Talabot thudded us into movement again, I headed over with great anticipation, for my first experience of Shackleton playing live. The Lancashire man has had an obsession with tribal drums ever since his first releases on his and Appleblim’s Skull Disco label got drawn into the dubstep scene. His new show is called Powerplant, so it was appropriate that it should be performed here – but I wasn’t prepared for the double onslaught of two giant sets of upright drums, battering our already battered senses in a godly cacophony of rhythms while Shackleton himself created twinkling, transcendent soundscapes. Epic music, and an epic end to a festival that is at the razor’s edge of worldwide music and culture.