The UK music press is still talking about “the South London scene”, but for many the periscopes seem to be permanently facing the likes of Shame, Goat Girl and HMLTD. If you’ve spent any amount of time eavesdropping in the smoking areas and live rooms of the capital this year, though, the name Black Midi will have cropped up more than any other, as they’ve garnered themselves the title of London’s most compelling new band. They regularly play at venues like The Windmill in Brixton, but are infamously elusive online; their digital presence is limited to one studio recording, an esoteric Facebook account and a few rough live videos on the South London archivist Lou Smith’s YouTube channel.

Meeting Black Midi for a drink in Effra Hall, a gorgeous pub just off Brixton Road, it’s difficult to imagine that this group of unassuming teenagers are the talk of the town. Lead vocalist Geordie Greep is humble and deflects all imminent praise with a wry smile. “It is what it is,” he laughs. “I’m glad people like us, but we don’t want to get bogged down in that.”

After talking to the band for just a matter of minutes you can quickly piece together that their lack of online presence isn’t a shrewd PR stunt or an attempt to create mystique; rather, that Black Midi are a shy bunch that have skilfully veiled their awkwardness.

It’s the same story when you see the band live: audience interaction is kept to a minimum while the group seem much more at ease communicating simply with each other. It’s all part of their musical chemistry, and their live shows feel like the product of a highly intuitive hive mind where individuality is not important. The focus is on each member’s contribution to perfectly executing the group’s bastard musical hybrid of clanging math-rock, visceral noise and frantic post-punk in the best way possible. At times it has a real sense of humour. At others it’s exhilarating. Sometimes it’s just bloody good fun. But Black Midi are deadly serious about their art and Greep constantly refers to the idea of ‘progression’.

“In two years, Black Midi’s music will be unrecognisable compared to what it is today,” he declares. “We just want to use the available resources to make something good. Make something good. Make something good. That’s our mission.” This focus is what defines the band far more than any catch-all genre term could.

Black Midi met at Brit School, a performing arts institution in Croydon that seems at odds with their music, on account of its celebrated mainstream alumni, which you probably know includes Jessie J, Adele, Amy Winehouse and bands like The Kooks. Greep and lead guitarist Matt Kelvin first dabbled in the idea of a band mid-way through their music course, when they were joined by drummer Morgan Simpson and bassist Cameron Picton. Diverse in musical influences and tastes, bonding over a passion for Talking Heads, Deerhoof and Danny Brown, all of them have been avid musicians since their pre-teens (Simpson allegedly having drummed “since he was two or three”). They formed “properly” last summer once they’d graduated, feeling prepared to start playing live immediately.

“You do shows every term and stuff,” Greep says, “so once you get out you’ve got a really good idea of how sound works. It meant we left school, could play at the Windmill and knew how to soundcheck straight away.”

Another product of this education is the very name of the project. “We used to have MIDI lessons, learning to make beats and that,” Greep says. “And I was like, ‘Matt, have you ever heard of this thing called Black MIDI?’” The band’s name refers to a Japanese Internet genre that consists of literally millions of notes inputted into an interface. “We thought it was a good name for a band,” he continues. “We haven’t spent more than five minutes watching a Youtube video on it, but that’s where our name comes from.”

Although the group have very little in common with their genre namesakes, the frenetic nature of the band is something that it’s hard not to notice.

When talk of the current South London scene comes up so too does the Brixton venue The Windmill – more so than some of the of the bands. The pub’s chief booker, Tim Perry, is among Black Midi’s biggest fans [it was Perry who first told Loud And Quiet about them when we were delivering copies of the magazine to the venue], and the group are quick to state that the venue is a force for good. “When we first started the thing, I sent emails to every venue in London,” Greep says. “The Windmill was the only one that replied… Once we played there once, we just kept playing there again and again. It’s really great for bands. Tim’s really great at what he does.”

For the most part of our conversation, Greep quietly answers the questions in a way that is calculated and subdued as he sups his tall glass of water, but when I ask about the group’s afternoon spent at Team Sport Mitcham (South London’s finest go-karting centre where Black Midi regularly meet to unwind), his face lights up. “It was so good, man, you go on the go karts and it’s so amazing. He won the both times,” he says, pointing to guitarist Matt Kelvin. “It was so much fun. I wish you were there. It’s just fast and furious, man.”

He stands up and gestures about a near crash before excitedly telling me about his love of bowling. It’s evident from both their onstage chemistry and dynamic elsewhere that this is a band built upon a solid friendship. You can even hear it in debut single ‘bmbmbmbm’, released via producer Dan Carey’s Speedy Wunderground label.

“Tell me about your debut single, be-em-be-em-be-em,” I ask the group. Greep looks back into my eyes and says: “Boom, Boom, Boom. That’s how the song goes.”

“It’s funny, because no one really says it like that,” Kelvin interjects. “Dan Carey wanted to put that one out. I think it’s most immediate, and the one that people seem to latch onto,” adds Greep.

Five minutes in length, it starts with a chugging guitar riff akin to a clean-cut version of ‘Something’ by The Butthole Surfers, before Greep’s maniacal howls turn the song into something else entirely. His vocals are the best thing about the song; goblin screeches and tetchy repeated motifs place the band’s sound somewhere uncanny. “I just try and sing in an interesting way,” he says. “I’d rather do something poorly that’s at least unique, rather than something widespread in an adequate way.”

Piercing, demonic and often operating as another jarring layer rather than a narrative Centre point, Greep is a volatile force at the helm of Black Midi; where everything else feels calculated. He feels like a feral dog ticking and scratching. Behind him, a razor sharp rhythm section keeps everything moving along with a steady immediacy. Morgan Simpson’s improvised drum fills are “the key” to the band’s regimented stomp, whilst Greep and Kelvin’s guitars constantly sound like a hexen battle cry. Live, they are an absolute unit, a singular power that is unlike any other currently playing in a pub near you.

Black Midi’s music is an enigma, but for the most part the group are very much shy and unassuming. They might be the talk of the town, but their introverted minds are elsewhere. “We’re not wild guys,” Greep mutters, “we really don’t go out partying.” Quite. Greep is visibly disinterested by talk of hedonism, but his face lights up when he finds out that I share his passion for composer Meredith Monk.

Approaching a state of notoriety only through word of mouth, bands as elusive as Black Midi are rarely as interesting in the music they make. It’s hard to work out whether they’ll be at ease with the attention coming their way or not. This is the group’s first proper interview and they stick to sentence-long answers almost without fail. It’s difficult to imagine them becoming the indie music press faces that Shame have become over the past six months, and it’s difficult to see them finding an audience as large as Goat Girl or Fat White Family across the rest of the country. But what Black Midi have done already is showcase an obnoxious, upsetting amount of potential, and accumulate a following of people that might have been drawn in by the enigma but who are sticking around for experimental guitar music that could go just about anywhere next.