MGMT are just the best . They're the only reason I'm here," squeaks rocktress Juliette Lewis with a girlish enthusiasm that's 35 going on 15. "Here" is Hollywood's legendary Avalon Theatre, where MGMT - indie rock's current duo of choice - are playing. Tonight in LA, they are headlining Design For Humanity, a huge environmental charity event. The Pussycat Dolls may be shooting their new video on the next block but, as Lewis knows, this is the only place for in-the-know Los Angelenos to be.
MGMT's performance is appropriately bombastic. Enrobed in a tie-dye pashmina complete with Jimi Hendrix print, vocalist and guitarist Andrew VanWyngarden does his best to channel the spirit of 1967, while co-pilot Ben Goldwasser skulks behind his keyboard. Both are sporting their trademark headbands. During anthemic closer Kids (the neon pop highlight from their debut album Oracular Spectacular, easily one of 2008's best) dozens of opportunistic fans rush the lacklustre security and storm the stage. Amid the chaos, a photographer, taking a punt, mounts a speaker stack and almost falls on top of Andrew as he shoots a close-up. Andrew doesn't flinch. In the past six months these scenes have become the norm.
Backstage, post-gig, glamazon fans with perfect Valley Girl drawls mill around (the band's support act for this charity benefit was a catwalk show). While Ben is taken, baby-faced Andrew is young, free and single and has the pick of the crop. Throughout the evening he's enveloped in a sea of fake tan and floral prints. Yet, as well as a lust for psychedelic pop skin, these girls have another thing in common; they're all wearing matching billowy dresses and have headbands over their curly tresses. It doesn't take a Topshop fashion buyer to realise they look ... just like MGMT! The band's brand of hippy quirk is spreading.
"To have the fans wearing headbands is funny," Ben says later. "We've been wearing headbands since we were at high school because we both have too much hair and don't know what to do about it." Andrew pleads innocence too. "It was neither us nor the label who figured out a style for the band. We never said this is how we were going to look like," he says. "There is no thought behind it." The morning after the Avalon show, amid much coded conversation about girls from the night before, Andrew reflects on his performance. "The mushrooms spoke to me last night. I was really, really feeling it," he says, and just to prove it he falls asleep mid-interview. Catching himself he apologises profusely, "Oh my god! Did I fall asleep? I'm so sorry, man..." Ben looks at his bandmate and laughs knowingly.
When Oracular Spectacular was released earlier this year it shone like a diamond in the black morass of schmindie rock. As likely to be found rummaging around in Bowie's dressing-up box as they were in Prince's purple sex dungeon, MGMT mixed psychedelic rock with joyful electro-funk. It pierced the UK albums Top 10 and - alongside Black Lips, Battles and Vampire Weekend - signalled a new breed of non-European bands reshaping alternative music. Their calling card, meanwhile, Time To Pretend, was chosen to soundtrack the grand finale of Skins (and its US equivalent Gossip Girl). As a measure of their success the 25-year-olds are playing Glastonbury's John Peel Stage this weekend above the Ting Tings. "We're really excited about playing a festival with thousands of different villages," Ben says. "It's great for people to escape everyday life and flip out."
Hammering home their hippy schtick, their official website says: "40 years after The Summer of Love, MGMT are celebrating the grand re-opening of the third eye of the world." Um, right.
Not everyone is as enthralled, though. The naysayers have chastised them for being "about as psychedelic as a Nurofen". "But it's not us - we never said we were 'psychedelic'," Andrew argues. "Critics have added their own mythology to what we are doing - saying we were bringing back a new rock revolution and hippy culture. We never said that." But what of the lofty third eye proclamations on your website? "Look, we're just messing around with the music and doing what we liked." Elsewhere, internet rumours have also claimed they "did a Milli Vanilli", citing producer Dave Fridmann (Flaming Lips) as the svengali behind the band, claiming he wrote the more complicated parts of the album. Ben's cooler than ice cold demeanour gets visibly flustered at the suggestion. "That's bullshit. Not to discredit him because he's a genius. But it wouldn't be fair to him to say that he 'took control of the band' or whatever these keyboard geeks are saying. He was very considerate and compassionate about helping us get the sound we wanted with drums and vocals - that doesn't mean he actually wrote the damn thing!"
That afternoon MGMT head to the studios of Sesame Street-on-acid US kids TV show Yo Gabba Gabba! For their appearance, MGMT dress up as DayGlo vikings complete with purple wigs and neon yellow socks. Holding up huge spear-like paintbrushes, they ride a boat shaped like a huge pigeon while painting a huge cartoon sky. The scene could be an art college installation echoing MGMT's early career emphasis on the visual. Forming six years ago when they were freshmen majoring in music at Wesleyan University in Connecticut (past alumni include Santogold), neither took it seriously. "We were just fooling around playing campus shows in people's dorms," says Andrew. "Fooling around" at one show included dressing up like dinosaurs while singing a cover of Genesis' Invisible Touch (watch it for yourself on YouTube). "At one show we decided to see how much candy and pop we could eat and drink before we peed ourselves on stage," Andrew admits matter-of-factly. "It was really high concept," chortles Ben.
Although MGMT's initial sets were filled with covers (from Pink's Get The Party Started to Nine Inch Nails' Closer) the band were writing their own material. One early song was Time To Pretend. Musically propulsive, the song combined a gloopy keyboard riff with Beach Boys-style harmonies and already feels like the song of the year. But it was the lyrics - which project a rock star trajectory, getting famous, getting druggy, dying by vomit-choking, all the while being "fated to pretend" - that have made it a bonafide anthem. Andrew wrote the words as a joke. "It was a running joke because it was so the opposite of where we were when we wrote it - we were just at university making 'dinky songs'. That's the irony." Is it weird to sing those same lyrics now? "Yeah," he says. "When I sing it now it's different - I get sad."
The band originally released the Time To Pretend EP in 2005. Recorded in a closet-sized studio, it was filled with "dinky", Vocoder-assisted electro pop tunes that contained no hint of the 'shroom-fuelled psychedelia that was to come. A show in a friend's kitchen in Massachusetts saw them take their onstage hijinks to another level playing the whole gig covered in melting butter. In the audience were members of Of Montreal who were impressed enough to offer them a support slot. They agreed but MGMT's inaugural tour had gig-goers scratching their heads, mainly because much of the band's set was spent trying to control an unwieldy prop they refer to as the "cheese pie". After the tour ended the band faded out, going back to their day jobs. Unbeknown to them however, MGMT were fated to pretend. An A&R scout at Columbia Records had belatedly discovered their EP. A meeting was set up, but they weren't convinced. "We didn't get it - why did they want to sign a band they hadn't seen playing live?" Ben asks. "It was like a man and a whore," Andrew interjects. "We were the whores and they fell in love with us. We said, 'Don't fall in love with us, it won't be good for you', but they did anyway."
Things aren't slowing down - ideas for the future include a mini Halloween Festival, a Chemical Brothers collaboration and a new album which they'll be writing "somewhere in the Caribbean" that will sound like "a darker Isley Brothers". "It's amazing that it's real," offers Ben. "Because it really did start off as a bit of fun." And off he goes, in his Viking outfit, back to the Yo Gabba Gabba! set. As he splatters Andrew's purple wig with bright yellow paint while their specially written track, The Art Is Everywhere, plays in the background, it's clear that the fun is most definitely continuing ...
· MGMT play Glastonbury tonight. Glastonbury Live continues Sat, 4.15pm, BBC2.
Oracular Spectacular is out now