There’s a story going around about Sleigh Bells. It’s about how the New York duo met, and it’s a tale so filmic and improbable that it might be a lie. You may well have heard it already, but that doesn’t make it any less worthy of being told again.

“I was waiting tables in this restaurant in Williamsburg,” begins Derek Miller, politely indulging our want to be told of this encounter firsthand “and Alexis was there, eating with her mum, and I was waiting them. Her mum was really talkative and friendly so she struck up a conversation with me and we ended up talking about what I was doing in New York, which was, at the time, looking for a female vocalist…”

“So my mum was like, ‘oh, my daughter’s a singer’,” picks up Alexis [Krauss] on cue, impersonating a typical mum’s voice. “And I’m like, ‘muuuum, shut up!’, kicking her under the table. So Derek told me a little about what he was doing and it turned out that we lived two blocks away from each other. We exchanged emails and met up in a park between our two apartments. Within a week I was shouting into an internal mic on a laptop, and that was Sleigh Bells!”

Even in this abridged version there’s no denying that real life people aren’t meant to meet like this. This is rom-com land. This is how Hugh Grant stops being a lonely, lovable fop and starts dating a woman far too perfect to be single in the first place. This is a fantasy daydreamed by those girls in any given TV advert sound-tracked by ‘Here Come The Girls’!

Derek and Alexis haven’t fallen in love, though – not in that way. They’ve become unquestionably close through their cut’n’shut, riffy, hip-hop electro, but they’re not dating. And while their chance meeting is made borderline eerie by just how synchronised their musical minds are, Alexis was probably the only girl that Derek came across and didn’t ask if they were a singer. Perhaps he was intending on asking her mum.

“Yeah, I would ask every girl if they were a singer,” he confirms “but they wouldn’t take it seriously – they’d think I was hitting on them, totally.”

“Maybe if we’d met in different circumstances I would have thought that,” says Alexis “but by that time we’d talked for ten minutes every time he’d come over to our table. I thought he was going to get fired.”

“And I thought you could tell I was sincere as well,” Derek says to Alexis. “I had a method of trying to describe what I was looking for because I was so used to doing it. You could probably tell that I wasn’t fucking around. I was focussed. It wasn’t like, ‘yeah, you wanna come to my place and look at my four-track?’,” he says adopting a dumb-ass jock voice and laughing.

Alexis emailed Derek that night, and by the end of the summer (2008) she’d decided that she’d not be returning to her day job as a fourth grade teacher. “My heart was pretty set on either staying in the classroom or doing something else around education,” she says “so it was a pretty big gamble for me. It was like, ‘oh, okay, I’m not going to go back to my salary and benefits and we’ll see what happens.’”

Derek had moved to Brooklyn from Florida (having already combed California for a suitable female singer), waited tables and been known as ‘the guy with the wanna-be-in-my-band? line’, but his unwavering perseverance – helped by a huge chunk of luck and a friendly mum – had finally paid off. Having had a six-year break from making music after the demise of his hardcore band, Poison The Well, he’d found the perfect voice for his new project. And although Sleigh Bells is now shared between two, the duo’s original conception very much happened in the mind and bedroom of Derek Miller. The metal guitar riffs were his, the processed beats and bass and synth parts were; he even had lyrics ready by the time he waited on Alexis’ table.

“I had quite a big break because I didn’t like the material [of Poison The Well] anymore,” explains Derek. “I was bored of it, so I was just trying to find a sound that I thought was interesting and worth doing again.”

But there’s still a hardcore influence there.

“Absolutely,” he agrees. “And I’m getting more comfortable with that as well. ‘Tell ‘Em’ [the band’s new single] is the most, quote/unquote, ‘metal-influenced’ track I’ve written, with the guitars, and that’s one of the newest tracks on the record. For me, when I quit Poison The Well I was so sick of heavy music. I wasn’t doing anything with any kind of intensity for a long time. And then over the years I kinda slowly started coming back to it because I was missing it. And so I think the challenge was to try to make music that had that confrontational quality but without being macho and stupidly violent, which is where the girl in my head came into the picture, because it counteracts the heaviness.”

Back to the fairytale meeting for a minute: it wasn’t just that Alexis was a singer in the sure-we’ve-all-got-a-singer-in-us-and-my-Alexis-even-sang-in-a-school-play-once sense of the word. Her raven hair and half-sleeve tattoo may have you believe otherwise (much like neither are hardly typical of a fourth grade teacher) but Alexis is an ex-pop star, and an experienced session singer. She spent part of her teens in RubyBlue, who were a bit like a sugary, teen pop version of Hepburn, making them well worth a search on Youtube.

“The only direct line between that and Sleigh Bells is that I worked with a lot of different people,” she explains. “I’ve worked with a lot of different writers, sang a lot of different styles. It meant that I wasn’t necessarily timid or inexperienced. Like, when we got together it was like, ‘ok, we’re working on this track and it’s another challenge’. It was different, which was what made it so exciting. Obviously I have a pop sensibility because it’s music that I’m very familiar with but in terms of it being plugged straight into Sleigh Bells, no, we developed the sound.”

“Alexis is fearless,” says Derek.

As for debut album ‘Treats’, it’s no shrinking violet either, rather a hell of an argument for such cross-genre-pollination. Disregarding the gloriously sweet, downbeat pop of ‘Rill Rill’ for a second, if it’s not Derek’s vision fully realised (amply mixing intense confrontation with playful, non-macho innocence) there’s probably no pleasing him. Fortunately, it is.

Opener ‘Tell Em’ is the record’s suitably toxic aperitif, all devilish Slayer riffs and electronic detonations. It – like most of the aggressive fun to be had with Sleigh Bells – has Derek shredding to a heavy bass blasts, kept in time by old-school hip-hop snaps. The low-end of ‘Kids’ could then have Snoop Dog’s ride out-bounce NWA’s without the need of hydraulics, while ‘Infinity Guitars’ fails to behave itself, running into the red and become a very fuzzy, very loud, tribal take on noise-pop. Occasionally Alexis slow raps angrily, but largely she sings the way a girl who used to be a teen pop band would do, making everything not just palatable and less dumb but wholly unique. It’s hardcore meets hip-hop; gnarly electro meets commercial pop. It’s bassy and heavy, yet tuneful and angelic at the same time. It’s basically the sound of the most melodious metal band you’ve ever heard being produced by N.E.R.D. and fronted by a classic pop star… who’s a tad prone to schizophrenic bouts of rage.

“I was just sick to death with the sound of a rock drum kit,” explains Derek “just the thought of boom, boom, ka. No more snares!” he says. “I can’t hear any fucking snares! So I got really addicted to hip-hop and production and those sounds are so much more exciting. And as a songwriter, before I got into beat production, I was just so jealous that they had all of these sounds at their disposal. Y’know, it could be a clap, it could be a snap, it could be fucking horns – you can sample and do anything you want, and that was very inspiring, as opposed to high-hat, crash, ride, tom. I can’t handle that shit. I love bands, but I couldn’t do any engaging in that. I also found rhythmically that a lot of hip-hop is heavier, like with the low-end that shakes, it’s a similar quality to when you first hear punk or hardcore.”

In the lobby of The Princess Barcelona, flight cases are scattered around and good haircuts chatter away, trying to remember when they last saw one another. It’s a day-long junction for some; a chance to bump into old friends for an extended weekend for others, until Primavera Sound 10 (a vast collection and celebration of indie All Stars) is over and the hotel’s inhabitants scram to their respective shows in any given country on earth.

On his way from the lift to the bar Derek runs into Surfer Blood, who once made up Sleigh Bells Mk I. “They’re my boys,” he says “We were playing together back in Florida. It had certain characteristics of what we’re doing but we all had our own ideas. I’m pretty controlling and I like to do everything and those guys have a tonne of ideas, clearly. So it made sense – we weren’t very serious and I said, ‘I’m going to go to New York’, and they were like, ‘cool, we’re going to do this.’”

Moments before that Derek had been in the lift with tonight’s festival headliners, Pavement. Or Stephen Malkmus, at least. “I nearly said to him, ‘yeah, thanks, we’re the band that have to go up against you tonight!’.”

Despite Primavera’s six stages, Sleigh Bells really are the only band that clash with the festival’s biggest draw. All arenas except for that of Pitchfork’s have the good sense to not take on the San Miguel stage from 1.15am, which will be graced by Pixies and The Pet Shop Boys over the following nights. Thirty minutes into Pavement’s set of slacker hits though, the size of the crowd in front of Derek and Alexis gives off the impression that no other band is currently playing in the whole town. Certainly no other band as heavily rhythmic as Sleigh Bells are. They sound brutal and distorted, like the earliest demos of ‘Crown On The Ground’ and ‘AB Machines’ promised – all levels pushed into the red to blow the speakers. Derek picks up his Gibson SG (a guitar favoured by proper ROCK bands) and starts it crunching around the ears of those in search of an early morning, girder-shaking party. Alexis arrives like the Tasmanian Devil, spinning across the stage, loose-limbed and thrashing her head.

Again, it’s a story that you might already be familiar with – Sleigh Bells’ live shows have already garnered them a lot of warranted attention, much like French electro thrashers Kap Bambino’s once did. At this year’s Great Escape (“One of my favourite shows we’ve ever played,” says Derek), the duo closed the Brighton festival, sonically rumbling the stage and encouraging an audience invasion that could have levelled the thing – standard practice at a Sleigh Bell’s gig, like Pete Doherty forgetting his words or Iggy Pop forgetting his shirt.

At Primavera the audience remains on its side of the crash barrier (not least because it takes quite the leap to make it onto any distant festival stage these days) but most seem to know all of the words, despite ‘Treats’ not being released in Europe for another month.

“If you come and see us live, basically expect two people running around like idiots,” laughs Derek. “It’s just the two of us, we don’t have any production or lights. It’s really just us and we both love dancing and jumping around, so there’s a lot of that. And hopefully the crowd will put their fists in the air.”

For black sheep ‘Rill Rill’ is more open-palms-feeling-the-coastal-breeze than clenched fists punching it. It’s ‘Treats’’ purest slice of FM pop, featuring piano chimes and the toll of romantic bells rather than shrill guitar riffs. Comparatively, it’s the band’s ‘Paper Planes’; a moment of crystalline clarity tucked amongst all of the abrasive madness and urban attitude.

“It kind of sets us up to do whatever,” explains Derek. “Besides really loving the song because I like the vocal on it so much, I really like the idea of having a song like that and then a song like ‘Tell Em’. It’s like we can make a metal record or a pop record. I don’t feel restricted or inhibited in any sort of way, creatively, and that’s so refreshing. Because you’re usually there with the same four guys, and those are your limitations, your instruments. I feel like we can go anywhere.”

“And we’ve talked about that,” adds Alexis “completely seriously for the next record. There’re loads of sounds we want to explore, from whispering to…”

“We were talking about stamping on tables and Alexis whispering,” interrupts Derek again “so part of it is so fucking loud and there’s also something really subdued.”

How subdued are we talking? Lounge R’n’B, or The xx?

“I’ve been listening to that record a lot recently,” says Derek. “For me they’re the antithesis of what we’re doing, which is awesome, because there’s so much space in that music, and we obviously like to cram a lot of sound into a small a space as possible.”

Sleigh Bells’ inspired intensity sure is impossible to ignore, but so too is the hype surrounding them at present. Blogs will tell you that they were ‘the best thing at CMJ this year by a country mile’, and it’s quite believable that they were. Still, a duo, from New York, made up of one skilful dude and an unfeasibly charismatic female performer, dabbling in harsh, bedroom-produced electronic pop music? It smacks of fad, and neigh-sayers, afraid of fashion because nothing cool can ever be genuinely good, are bound to pick up a certain stick to beat Sleigh Bells with if they don’t find ‘Treats’ as tasty as expected. And that stick is shaped like M.I.A..

It was the baile funk-stress who first discovered Sleigh Bells, and promptly signed them to her own N.E.E.T. imprint in the States. And after listening to ten seconds of any given Sleigh Bells track, it’s easy to see why it was MIA, in particular, who was so instantly excited. She’d heard the super-aggressive, static-bashing ‘Crown On The Ground’ (the cracked demo of which was too visceral to recreate or improve upon so the band used the original five-dollar recording for the finished album) and ‘AB Machines’, which sounds like a menacing Prodigy/Suicide collaboration. Both tracks are so rude and popping with urban deviance that they could be lost M.I.A. songs.

“She was one of the earliest supporters of ours,” smiles Alexis. “She heard it over an iPhone.”

“Yeah,” nods Derek “she emailed us immediately and came to New York soon after that. It was very exciting because just our friends were listening to the band before that.”

Alexis: “And at that point there was no critical response to us, she didn’t need that. It was purely her own visceral reaction, and you don’t find that very often. Most people wait for the jury.”

Derek ended up working on M.I.A.’s forthcoming, third album, but the favour wasn’t returned, on the band’s wishes. They were well aware of the stick.

“We spoke about that a bit,” says Derek “and it would have been amazing to have her guest and do some verses, but we made a point of not letting anyone in. I wanted to produce the record, we wanted to do it front to back ourselves. That way any of the flaws were our fault but also any of successes were ours, because especially after the fidelity of the demos was so low – which was just due to limitations – I knew that broadening the sound, if there was another producer, everyone would have been like, ‘lucky for them that they worked with ‘insert name here’. And fuck that! This is ours!”

“And having someone like M.I.A., who is obviously incredible, people automatically assume that everything that’s good about the record is her,” reasons Alexis “because they love her.”

Derek: “And that’s terrible, because it’s never yours, and people will always hold that over your head, and they’ll love it, especially if it succeeds they will love poking you with that. And now they don’t have that weapon, and I couldn’t be more pleased.”

The M.I.A. association has largely been a blessing, from the record deal to the spotlight shone at Sleigh Bells’ spotlight-less live riots and the belligerent electronic music they muster up, but there is a risk that some will start to disregard the substance that comes with the band’s definite style, and their hip celebrity connection. They don’t care, of course, because they’ve heard ‘Treats’. They know it’s the most exciting sounding record around, because they made it, from hip-hop nuts and brash electro bolts, and decorated it with teen pop streamers and thrashy hardcore flags. And it’s not as if you don’t learn a thing or two while being in RubyBlue or Poison The Well.

“This is the main thing, for me,” enlightens Derek. “Just ignore everything! Ignore the good stuff, ignore the bad stuff, wake up, go to sound-check, play the show, get in the van, go to the next city. And just make sure you enjoy it.”