The concept of 'play' - that is, in the dada-surrealist sense of the word - follows that by playing games we will open doors away from orthodoxy, breaking the shackles of rationalism so as to achieve true chaos, purity, nirvana. In this way, over the last decade Animal Collective have emerged as master surrealists. Experimental as they are unpretentious, and resolutely altruistic, if there's one word to describe the Baltimore four-piece it's 'playful'. And the games they played unlocked new ways of making pop music.

With 2008's celebrated Merriweather Post Pavilion, Animal Collective consolidated a career’s worth of loosely tied brilliance, in such dazzling fashion that it took even longtime fans by surprise. Reinventing hippydom for the chemical generation, this was an album that burned when it should have dissolved, which laughed as the electric thud of childhood's warm summer blood ran cold, which exploded at the very dead-end of peacefulness, and which at every stage rendered the listener an object inside, looking out. Merriweather Post Pavilion offered something extremely rare in the music world; a type of art inspired not by rebellion, adversity, misery or love, but awe. The awe of seeing the world for the first time - feeling everything all at once, just as a child would. It hung in a permanent hold of pre-sexual, epiphanic ecstasy, too involuntary, powerful and overwhelmingly sincere to be considered twee.

Four years after Merriweather Post Pavilion, today sees the return of Panda Bear (Noah Lennox), Avey Tare (David Portner), Deakin (Josh Dibb) and Geologist (Brian Weitz), who January past decamped to El Paso, TX with the intention of, once again, pulling the rug from underneath pop music. Amongst 2012's most eagerly anticipated albums, co-produced by the band and MPP's Ben Allen, Centipede Hz marks a transition from the reverbed ambient of past albums into more rough and ready climes. Every song on Centipede Hz was designed to be played in a live setting, making AC's 9th studio album unlike anything that has preceded it, building on MPP's panoramic scope but altering the formula in myriad ways. They do play their little games.

'Moonjock'

A ceremonious “This… Is…The… News” opens Centipede Hz, followed by the sound of inter-bleeding radio transmissions and a countdown: “5,4,3,2… ONE ONE ONE ONE ONE...” The next sound you hear is pistons of processed rock guitar. It sounds like Sleigh Bells. Out with the old, in with the new.

Letting us damn well know that they're back, 'Moonjock' is relentless as it is volcanic. Like a Michel Gondry montage it seems to spin, scattering a dizzying array of choruses, bridges, breaks, crescendos and peaks - what could be 10 independent sections but what feels like a hundred. Imagine 'In The Flowers' mid-point flash in cubomaniacal battle with The Beatles' entire back catalogue.

Moreish sing-a-longs beget soaring choirs, heralding boogying spurts and electronic sea shanties, giving way to a megalithic drumline - the war tattoo that drives a marching army of game sprites. Followed by what you imagine Rolo Tomassi would sound like if they ever covered 'Three Blind Mice'.

What emerges is a system of greased illogicality. 'Moonjock' is a cheat; a series of highlights - pop without the downtime. Animal Collective, you see, are all about impossibility.

Each 'moment' is nevertheless strung together using real judgement. What is often misconstrued as autonomic sketching, AC's music belies a light touch and real craftsmanship; a six sense for when to ebb and when to flow, but in hyper-time. It's making it seem spontaneous that is the real trick.

Arguably there is nothing unprecedented about 'Moonjock'. As far back as 2007's Strawberry Jam they've written erratic, barreling songs that bend the rules of pop dynamics (e.g 'Peacebone'). Of course, 'Moonjock' happens to be that bit more anarchic, as well as quicker paced than is customary for AC. But that's not it; that isn't quite the adjustment here. The difference is a slight but crucial change in tone.

Whereas before their method of expressing boundless joy - those tumbling-over-themselves structures - was rooted in serenity, here there's something almost hungry about their quest for bliss. You could describe it as intensity. It's as if their fractured schemes for the pursuit of pleasure have become destabilized, curdling into volatility. Certainly, Avey Tare's screamed “Wot!!!!” sounds far more like a gesture of dissent than it does acquiescence.

It's a new look that represents a departure for the band: a departure from sentimentality, their folk-hymnal roots and, theoretically, by extension their obsession with childhood. Or even childhood itself. It's exciting. It's a new edge.

'Today's Supernatural'

Centipede Hz sees Panda Bear on live drums for the first time since 2003's Here Comes The Indian. There's also the return of guitarist Deakin, who sat it out for the dance-influenced Merriweather Post Pavilion. Meanwhile, they opted to write the album in a room together, jamming, instead of composing by file-sharing between emails, as was how MPP came to be. It's for all these factors that, occasionally, Centipede plays like AC's prog-rock album.

Continuing 'Moonjock's fractious tone ("Sometimes you've got to get ma-aa-aa-d!” screams Avey Tare), the instrumentation on 'Today's Supernatural' is raw: creaking 60s psych-rock organ, stubby bongos and stabs of crunchy guitar (the most surprising new addition to their sonic palette). But it's Avey Tare's vocals that make the biggest impression. The first thing you notice on Centipede Hz is the scarcity of harmonized vocals (another snub to their folk roots), divesting their sound of its dreaminess. But when, as on 'Today's Supernatural', the vocals form a ragged scream - high in the mix and naked above the underlying shroud of lush textures - the effect is a mighty big bolt of realism. And it's here where Centipede Hz's most interesting track gets interesting.

The closer Animal Collective sail to realism, the more unbalancing their music. They've always traded on the tension between the bucolic (i.e the real) and the electronic (the unreal). And quite often, so deft is the balance you're never quite sure if what you are hearing is one or the other. It's mind-tricking as opposed to (as with old school psychedelia) mind-altering. And like any magic trick, the defter the act, the less able you are to work out exactly how the trick is done, and the more likely you are to believe in the magic. 'Today's Supernatural' features drum rolls and crescendos that seem real but couldn’t be. In the meantime it's ever so slightly accelerated for rock music, and ever so slightly machine-like in it's motion. Human but inhuman. Then there's Avey Tare's voice: waterlogged and glitched at some points, while at other times harsh and throaty. 'Today's Supernatural' is meaty, live prog-rock - physical and bulbous. But not once does it seem to have existed in real space. Quite simply, it sounds like magic.

Most of all you're reminded that, 50-odd years on, electronica remains able to accomplish what rock music cannot on its own. The bad news is, 'Today's 'Supernatural' telegraphs Centipede Hz's shift from 'techno-inspired' to 'rock-inspired'. Taking their cues from fellow Baltimore native and glow-stick baboon Dan Deacon, MPP's 'Summertime Clothes' and Strawberry Jam's 'Peacebone' plied a thumping repetitiveness that fully aided their expressions of wild wonder. Still, there's always Delorean.

'Rosie Oh'

The closest Centipede Hz comes to straight-up guitar music, though this time conducted in a more terrestrial fashion. Nonetheless 'Rosie Oh' is, by conventional standards, weird as fuck. Perfect for fans of electronica-period Super Furry Animals, it's a fungi-stinking, moss-caked 70s prog-pop vignette by way of Lewis Carroll. With Panda Bear taking over from Avey on vocals, around Deakin's dancing guitar all manner of computer-born critters convene, late... late... for a very important date. We aren't being cute here, it really does evoke the image of a rabbit, some cartoon crickets and a bird, hurrying towards some type of fun-ass party. If only the Fingermouse guy was still around. He'd be on the riverbank with the rest of the animals.

'Applesauce'

And so begins a three-part run of vocal-led, melodically gorgeous and structurally settled tracks – none of which move the Animal Collective sound forward in any significant way. Let's call this suite 'traditionalist AC'.

Centipede's Hz's least progressive track, 'Applesauce' recall an albeit tranquilized off-cut from the first half of Merriweather Post Pavilion. Beginning with the kind of short electronic preamble that riddles MPP, Avey jumps straight into the lead refrain (another MPP trope). The lyrics and sonics are symbiotic, channeling that staple AC theme of perfect wellbeing: “I'll eat a mango and I'll feel like a little honeycomb,” Avey trills.

The song progresses leisurely through varying blocks of electronically-cradled psychedelia, each with their very own designated melody. Sometimes the pace will spike and Panda Bear will smash his cymbals proudly; at other times the chirping background effects will follow Avey's vocals down the rabbit hole. During weird tangents, he takes to twirling around like an giggling Enid Blyton character, bathed in scattered sonic light. The final act concerns some kind of game, like 'one-potato', and finishes on a resolved major key like a bow has been tied around it. It's a song that smiles with you. It tells you everything is fine.

'Wide Eyed'

It's with 'Wide Eyed' that Centipede Hz delivers on its subtext: a fixation with the AM radio signals deployed when the band were children, which they like to imagine still travel through space to this day. Written by Deakin, the song evolves in such a way as to replicate the trajectory of said ribbon of electromagnetic nothing, as 'wide-eyed' it traverses far-off galaxies.

The sizzle of a neon synth-line and Deakin's processed vocals lend a sci-fi feel, while the inter-textural album art - with its grids overlaying vivid contours - manifest in the blocky tech crisscrossing fleshy atmospherics and African percussion. Coupled with Deakin's voice - of a lower register and a more mysterious nature than Avey Tare's - it's a intriguing take on the cutesy idea of a radio signal with a life of its own. Towards the end the permanently shunting rhythm and flaring loops begin to melt, as Deakin's vocals descend into stuck-record loops and are then swallowed up by waves of interference.

'Father Time'

Like St Pepper's meets millennial post-indie, 'Father Time''s machine-diced psych-pop play's like a shronky Flaming Lips; but without the Lips' retro-futurist blues. Groovy organ and a children's choir are refracted by a clutter of technological verbiage, driven by Tare's dancing, acutely melodic vocals which are themselves distorted into a gurgling kind of autotune. Opening with a sample of menacing laughter, a key-warped Hawaiian lilt swoons as Avey Tare re-imagines the pleasures of fatherhood's most utopian moments as a quasi-psychedelic experience. As with any Beatles-ian psyche, there's darkness below the trippy serenity – the kind of 'nothing is real' angst that accompanies prolonged LSD abuse. Another 'classicist' AC tune, it plays like a electronic daydream in a forest clearing.

'New Town Burnout'

In stark contrast with 'Father Time', 'New Town Burnout' is, like 'Wide Eyed', somewhat denaturised. It's a further departure from rustic whimsy that may prove jarring for longtime fans.

Centipede's Hz's coldest track, it's balanced between the organic, swinging synthpop of Talk Talk and the textural harshness of the post-noise commonly found on the Editions Mego label. Crystalline rim-hits mingle with icy synths and a metallic low end, while a chorus of brassy bombast emboldens Panda Bear's relatively dispassionate vocals. Modally-sequenced vocal samples mellow the hit to a degree, but otherwise 'New Town Burnout' is another mechanical paean to space travel.

'Monkey Riches'

Overlong and lacking in structural narrative, the seven-minute-long 'Monkey Riches' is a tuneless, flat misfire. Driven by Burundi-like drums (imagine an African 'Fireworks') and Avey's squealed vocals (Billy Corrigan with a slapped face), it's a headache of thing. The final section is oppressively busy - cymbals, messy poly-rhythms and cluttering Black Dice-esque flotsam blurring into a turgid racket. The most frenzied track of their 10 year career, and its least interesting.

'Mercury Man'

If AC detractors claim the band's music is soullessly detached, 'Mercury Man' is a resolutely human affront to such accusations; a touching tale of machine melancholy reminiscent of Grandaddy's 'Jed' fable.

Churning in a riot of puppyish electronica and tribal drums, a ska-like rhythm provides the metric for Avey's heartbreakingly dejected vocals. He is the 'Mercury Man', imprisoned in fizzing digitalism and dreaming of life as a real boy. Imagining the joys of having a soul, he sings “Sounds like machines talking to me on the phone”, in the form of Centipede Hz's finest vocal melody. The pace increases and gradually anguish cedes to a celebration of life; but life as lived in any form, even an artificial one.

This is typical of Animal Collective. One of America's dying beed of authentic 'hippy' bands (they derive from beatnik royalty), nonetheless as optimists and indefatigable futurists they have always embraced the millennium’s technophilic existence, whereas lesser alt-bands will resort to the cliched theme of alienation.

Hymnal backing vocals and Panda's live drums push the song to soaring new heights, as with lump-in-the-throat poignance the Mercury Man accepts his lot in life as a synthetic person. A glorious track, here you can detect the pleasure the band are taking in playing together for the first time in years - liberated the dehumanising effects of programming overkill.

'Pulleys'

'Pulleys' is basically world music. Powered by Panda's careful heartbeat - dah-duh, dah-duh – and leavened by Deakin's Pete Gabriel guitar, the overall effect is a bubbling Yeasayer-like orgy of sub-Saharan mysticism.

'Amanita'

Taking its name from the powerfully psychotropic mushroom (think the classic fairytale version, or 'Mushroom' from Mario), 'Amanita' is pure psychedelia.

One of Animal Collective's greatest triumphs was to eradicate the final vestiges of psychedelia's fusty piety - injecting the genre with a dynamic sense of fun by supercharging it with tech (though, arguably, rave had already done the hard work). In that respect, 'Amanita' (and 'Rosie Oh' to a lesser degree) is a step backwards for them. With its combination of Marrakesh-via-Carnaby Street keys, lysergic guitar and bongos, it's all elbow-pads and sandals. Salvation from mundanity arrives with another gorgeous vocal melody and a final act of Mardi Gras delirium, sounding not unlike Ibiza pop filtered through 'Hounds Of Love'.