At 5am on Sunday morning, in the last hour of the last night of Barcelona's Sonar Festival, the sky opened up and dropped a hurricane mass of water on the sweating, glass-eyed crowd. It was torrential, passing through the stage lights in fat crystal balloons, creating a shallow pool in the arena where the most hardy, MDMA-fuelled dancers stamped their feet, water streaming down their faces. Finally, in its closing hour, Sonar mustered a worthy bit of spectacle.

DAY 1

“Richie Hawtin fans are necking the first drugs of the day”

Sonar Village

Billed as a world-leading celebration of electronic music and new media art, Sonar is a curious amalgam of club culture and cutting edge experimental electronica, where the former obviously pays for the latter. Spread across three days, two industrial warehouse complexes and separate day and night programs, the festival proper is surrounded by dozens of 'Off Sonar' club events, beach parties and label showcases and other ad hoc Ibiza-style gatherings. People come to Barcelona during Sonar to party 'til dawn, by whatever means necessary.

Given its reputation, the futuristic bent of electronic music and the scale of the event – more than 100,000 official ticket holders – you'd think the festival proper would be a visual trip, dressed big to complement the big musical line-up. But through the gates at the Fira De Barcelona, where Sonar By Day kicks off on Thursday afternoon, there isn't much to see except a field of AstroTurf and some hulking modernist architecture. Of the four main stages at Sonar By Day, only the SonarHall has any atmosphere. Draped in velvet curtains and stained in deep red light, the Hall hosts our first artist, with whose performance the dull festival landscape is forgiven.

Chris Madak (aka Bee Mask) carves a primordial, ectoplasmic universe out of tweets and glitches, the dawn of life on a cybernetic planet. Half the audience lies down to listen and the rest sits, enraptured with his glistening, knob-twiddling genius. Outside, Richie Hawtin fans are necking the first drugs of the day, inside we chin-strokers are in deep bliss over modern art so lovely it makes you want to pee.

On the SonarVillage stage, Danish firebrand MO manages to win over the bass-addicted audience with the sheer ecstatic violence of her performance, closing her set with a reckless bit of crowd-surfing that sees her planted suddenly in the middle of the crowd far from the stage.

MO

At 5pm, Sonar By Day hits an impossible peak with Nils Frahm's set, the German savant hammering out woodsy, spacious heartbeats on piano, organ and synth, his every muscle roped tight against bone, every inch of him dripping sweat. Frahm is wearing only one shoe and every inch of him is beautiful, even his sock. He floors us with Says, some Rachmaninoff-paced piano piece that blends Tokyo's frenetic streets with some pastoral English idyll and For Peter/Toilet Brushes, a closing epic that carries us to future past via Clockwork Orange and Bladerunner. (Surely we should just go home at this point, it can't get any better.)

Nils Frahm

Outside in the Village, things are heating up courtesy of Ryan Hemsworth, who brings the house-fuelled funk but is remarkable primarily for his animated dancing and overall hotness. Inside, a doughy looking Welsh kid, a Young Turks signing called Koreless, has less visual charm but is so astoundingly gifted that he seems beautiful anyway. He builds spectral landscapes out of sound, shies away from the drop, keeps his head down.

Ryan Hemsworth

Koreless

A pattern is emerging at Sonar. Some bass-heavy house or trance DJ makes with the boom-boom and the room is packed with sketchy looking kids doing the sway/march/arm-flap of the perpetually munted. The next set moves towards the art end of town and suddenly the room clears out. There is a divided audience here and the art kids are vastly outnumbered. It's a weird mix, strung together by the mode of production but planets apart aesthetically. No one seems to mind.

For the art kids, the day ends with a performance by Ben Frost in the air-conditioned darkness of the SonarComplex, a seated theatre with way too comfortable chairs. Frost debuts a new live set, featuring two drummers that face off in a tribal thunder of bass kicks and floor toms – one of them is clearly a metal dude, transplanted into Frost's brilliant electro nightmare. With blue spotlights folding across the blackness and Frost's staccato musical ferocity, it is a deeply surreal scene.

Ben Frost

Outside in the Village, Richie Hawtin revives his 1990's Plastikman persona for a live performance of 'Objekt', a show that debuted at the Guggenheim in late 2013. To distract us from the droning deep house, there is a massive LED-lit Obelisk in the centre of the field, flashing random rave-y patterns. It is less impressive than it sounds.

DAY 2

“I wasn't even high”

Back at the Fira, in the big red room, producer Matthew Barnes (UK) teams up with a guitarist and videographer for the 'Forest Swords' live set, a warm but grim electro/analogue amalgam for the post-dub world, drenching sounds that are the son of the son of Joy Division, brushing as close to indie rock as Sonar will provide. It is massive and beautiful. Thus far the festival is heavy on massive and beautiful, particularly in the SonarHall.

Outside in the Village, early rising EDM punters enjoy a series of beat-focused DJs, including an impressive Barcelona native by the name of DJ Der, who plays hypnotic house that hangs heavy in the musty, damp heat. But heat be damned, the kids are still dancing, and roving beer vendors are doing a massive trade.

There is a market hall where tech companies display sweet digital gadgets and DJ toys, a cinema where tech-focused films play, including shorts by Resident Advisor and the Stones Throw Records doc, and a conference area where talks and music hack days are taking place. There is a teeming VIP bar, which hosts low, middle and high profile clubheads and up a long flight of stairs, a disco space called Despacio, programmed by James Murphy and 2ManyDJs, where 50,000 watt speakers rearrange your organs and brain cells.

Throwing Snow

At the back of the Fira complex, the Red Bull-sponsored SonarDome is pumping for Pretorian crew Trancemicsoul, a hefty house-fused funk crew that enrapture the mid-afternoon, already totally fucked up audience. There must be a few thousand in there but they vaporise at the end of the set, when the experimental UK artist Throwing Snow takes to the stage to deliver his warped, haunted trance set. He creates tense sonic landscapes that belong somewhere else, not in the filtered sunlight of the Dome, which is basically an indoor football field. He belongs somewhere dark, late at night with the lights down low where we can sweat heavy on the dance floor with this future tribalist sound; his great oceanic drops. The setting is wrong but is amazing.

Back in the studiously atmospheric SonarHall, Simian Mobile Disco pull a massive crowd with their space doom sound, a full room of funky steppers and zombie marchers swaying along to the clockwork beat and scaling synth drama. Great music, terrible dancing. (What is it about dance music that produces such garbage dancing?) They are followed by late-nineties glitch legends Matmos, who speak directly to the split-personality of Sonar. “We hear you guys like a steady rhythm,” they joke, before setting off a metronome and blasting us with criminally loud abstract auditory violence. The only way to digest their visually excellent show is from the safe harbour of the adjoining hall.

Back up in the SonarComplex, Oneohtrix Point Never flattens us. His music envelopes the world, his videography is sophisticated, surreal, ethereal rapid-fire graphic eloquence, filled with molten wax models and a pastiche of cut-up words. By some cruel twist, his set overlaps with Jon Hopkins and we have to tear ourselves away, centimetre by centimetre. But fuck, are we reluctant. Jon Hopkins is worth it. The Hall is rib-to-rib packed and explodes for his Autechre-meets-Bro-step brilliance, his masterful tease, his monstrous big interpretations of the stunning tracks from Immunity. “I wasn't even high,” people mutter afterwards, dazed and astounded.

Oneohtrix Point Never

The party moves up the hill to the Fira Gran Via L'Hospitalet for the first Sonar By Night, in a series of cavernous interconnected warehouses dressed with multiple large screens and not much else. At the SonarClub, the main night time arena, Royksopp hits the stage with Swedish pop icon Robyn, who is a magical pixie warrior. She sings Call Your Girlfriend and segues into Dancing On My Own, and we grin spastically on an epic pop high.

Robyn

Punters pour through the doors, heavy bass breaks out on stages across the venue and the festival becomes a dark swill of MDMA and strobing lights. In the Club, Flux Pavillion is followed by Pretty Lights, Recondite and Richie Hawtin. There is a room where you can buy food and ride dodgem cars and listen to pounding trance, and two other stages that mix experimental acts with disco, funk and other cross-genre breeds.

Dodgem cars

Caribou appears at 1.40am in the SonarPub but his live instrumental set up falls a bit flat. Todd Terje follows him, a master of crowd-pleasing future disco, and exceeds all expectations, but the gongs for night one go to Gesaffelstein and Four Tet, both gracing the SonarLab stage. The former, a French tech-house master and Yeezus contributor, just fucking bombed the audience. His beats were like the onslaught of the calvary of Armageddon. But, you know, funky.

Caribou

Swinging in at 4am, Keiren Hebden was worth the wait. Opening with Body Feels from Beautiful Rewind and peaking with Parallel Jalebi from the same album, the understated uber-nerd delivered his trademark trance/deep house/experimental blend, warping the air around him with thickly emotive tunes. We float out of the venue at dawn, with Four Tet still glowing in our hearts.

DAY 3

“and just keeps going up, no drop; an epic, endless tease that makes our eyes roll back in our heads”

Big night, late start, and the taxis are having trouble reaching the day venue due to road closures. It's mid-afternoon by the time we arrive, and Neneh Cherry is in the Hall, playing tunes from her first album in 16 years, produced by Four Tet, granting her an awkward entre to this electronic music festival. Her grooving rock sound is daggy in context but the crowd applauds politely. Outside, Kid Koala is having a whale of a time in an actual koala suit, with Playboy bunnies dancing enthusiastically beside him and a sea of people hopping around in front. It's all a bit sketchy on day three but James Holden is in the headline slot in the SonarHall and he will surely save us with a live interpretation of his breakthrough album, The Inheritors. Sort of, not quite. He has a saxophonist on stage to play the jazz breaks from the album and it comes off a little cheesy, although the sound in the room is magnificent.

We give up and head to Sonar by Night, where Four Tet is warming the crowd in the SonarClub ahead of Massive Attack's set. His DJ set is radically different but every bit as good as his live show, blending spectral house, dub, reggae, African art rock and a free jazz track that seems specifically designed to fuck everyone's shit up. He's the master of contrapuntal mixing, resetting the time signature from track to track. There aren't many people around that early in the night, but everyone there is dancing.

SonarClub

Massive Attack have audio issues early in their set and several instruments aren't coming through the speakers, which leaves the heritage act sounding flat in the mammoth club space, particularly against the tide of spectators that has flooded in to see them. The visual design of their show is also kind of quaint, with brand names flashing across the screen in a militant late-nineties, 'No Logo' fashion. There is a lot of goodwill but the set is boring.

Massive Attack

Lykke Li, on the other hand, brings the drama to the SonarPub stage, an undulating wisp of art-rock beauty with bedraggled hair and a constant enveloping cloud of dry ice around her. No Rest For The Wicked is epic and the audience raises their hands as one and bellows along to the transcendent chorus.

James Murphy plays unapologetically crowd-pleasing disco punctuated by pop hits including Bus Stop and It Takes A Muscle To Fall In Love. Up next, Chic and Nile Rogers take it to the next level with a super hits set that makes the crowd go batshit crazy, including their slick-as-fuck mash-up of Good Times and Rapper's Delight.

As the hours wind on, Sonar By Night turns blissfully feral, just messy, messy, happy but messy; one or two punters collapsed on the dancefloor or dragged off to the medics, but most doing the march-sway-march thing, with occasional whooping. Walking through the halls, you're assaulted by bass pouring from dozens of world-class speakers; the light shimmers and dips and warps around you and the crowd seems to drag around like seaweed in shallow water.

We have one more great moment ahead. Just after a monster grime/rap/house set from Future Brown, James Holden hits the SonarLab stage to go B2B with Daphni (the alter-ego of Caribou's Dan Snaith). Rare blends of cosmic house, trance, psychedelia and God-knows-what else assail the wrapt crowd; tripping brain music with endless danceable beats, with Four Tet watching bemused from side stage and Daphni/Dan/Caribou grinning beatifically at his audience over his glasses.

Daphni B2B James Holden

Holden plays a track that climbs and climbs and climbs and climbs and climbs and just keeps going up, no drop; an epic, endless tease that makes our eyes roll back in our heads. And half an hour later, the lightening flashes and the rain comes crashing down.

Rain

All photos by Simone Ubaldi