After their initial shows at The Windmill (“The only place we played for a good six months,” says Picton. “Nobody else was interested.”) and a handful of higher-profile support slots, Black Midi formalised their relationship with the venue with a residency. As they were putting together the bills for each show, they spotted an opportunity.

“Tim Perry kept recommending this guy Dan Carey to us to record with,” says Greep, “so we decided to get Dan to come and play one of the nights. He played on the first night, and his band, Scotti Brains, were really good. We played, he liked it, he said, ‘yeah, come over, I wanna do that song that goes boom-boom-boom’, and that was it.” He stops abruptly. He does that a lot.

Carey, a highly influential figure in the development of many new South London acts, runs cult indie label Speedy Wunderground. ‘bmbmbm’ – another example of a more formal song title being shirked in favour of basic onomatopoeia – became their first single, released in May last year to rapturous acclaim. By that point, word had spread about this thrilling new band, partly thanks to the aforementioned NME article and NTS session. They paid little attention to the hype, though, and kept working at their craft at a frenetic pace, gigging relentlessly and finding time to work on more recorded music in between. Predictably, this impressive pace simply seemed like the natural thing to do for the four young men in the eye of this media storm.

“By the time it got to the point of making the album, we just recorded the songs we’d been playing at gigs,” explains Greep. “Most of them went through that process of scaling down and tweaking live, but by the time we were recording them for the album, we knew them really well.”

I ask if the songs feel old to them now, whether they’re keen to get them out into the public eye and move swiftly on now that the album is done.

Greep: “Yeah, but the way we’ve recorded them is different to how we play them live. We set out to make this different from the live thing; make the recordings stand on their own.”

“They don’t feel old, but we just want to keep moving,” adds Simpson. “At no point are we like, ‘cool, we’ve got these songs, let’s chill out’. Not that we’re not happy with what we’ve got, but there’s a natural drive forward.”

Somewhat unbelievably, some of the album tracks go all the way back to Kelvin and Greep’s brief stint as buskers in suburban Bromley. I find it hard to imagine hearing songs like ‘ducter’, the album’s jerky, shapeshifting closer, on my way to Gregg’s.

“We had all the parts [to ‘ducter’] and everything,” says Greep. “We were just jamming on the street, making it up. We worked out a lot of the arrangement there and then. We didn’t learn it as a band for ages. Just with electric guitars, a portable amp, delay pedal… it was funny.”

All four band members are enthusiastic when talking about making Schlagenheim with Carey. Greep lays out the process: “We did all the main stuff live and then added overdubs. Dan had this way of mapping the tempo onto the changes of the track so we could still sequence stuff onto it properly. He doesn’t try and direct us too much, but he’s not an Albini-style ‘just capture what’s in the room’ type either. He lets us do our thing but he has his own sound. It’s like the Beatles or something, making a recording for its own sake.”

“It’s a collaboration,” contributes Picton. “We’ve worked with other producers, with varying degrees of success, and it tends to be that the more relaxed the sessions are, the better. The best one that wasn’t with Dan was just in this guy’s bedroom, but we’ve done other ones in high-end studios, strictly to click, and we struggled. We’d get mixes back and they’d be lifeless.”

“Not to say those people aren’t good at their job – it just didn’t work for us,” Simpson reiterates, ever the diplomat.

Greep fixes me with another hard stare. “There’s a bit of an obsession with tempos not changing, and the isolation of instruments,” he says. “But if you put on any sick album, and count along with the tempo, it speeds up and slows down all the time and no one notices. Same with the isolation thing – no one cares.”

Simpson agrees. “It’s not the main focus. It doesn’t need to be.”

They’re all emphatic about the record being a standalone artefact; an entirely separate entity to the live experience.

“We all played different instruments on the album,” says Greep. “I played synths, piano and accordion, Matt played banjo… the whole point is we don’t wanna reproduce the album exactly live.”

“And it’d be impossible,” adds Simpson. “We’d have to hire four or five different musicians to do it. But it wouldn’t make any sense to be in a studio environment and not use what’s around you to enhance what you’re making.”

Greep is clear on this. “I don’t like paying to see a band and hearing something I could’ve heard at home. When you start trying to do that you’ve lost the energy. It’s pointless.” Again, they’re at pains to distinguish between what’s necessary and what isn’t, what’s valuable and what holds no interest for them. Their clarity of vision is striking.

The other thing I want to raise with the band is their technical accomplishment. Alongside Greep’s unhinged, squawking vocal style (a product of his desire not to simply ape “that macho thing that all the other guitar bands do”), it’s one of the aspects of the band’s sound that most divides opinion. They’re clearly technically excellent, but some people – myself included – aren’t always convinced that they manage to strike the balance between using those skills to serve their musical context, and simply flexing their considerable instrumental muscle.

“It’s not really a consideration for me,” says Greep, a little dismissively. “If you’re playing a lot, you’ll get more able. A lot of the music that I’ve liked over the years has been more demanding to play, and I just wanted to be able to play like that.”

I put it to him that limitations, however, can breed creativity, and sometimes being able to play whatever you want can be a little overwhelming.

“Yeah, for sure,” he replies. “But in the same sense, those limitations don’t necessarily make it good either. I know what you’re saying, but neither one is always good. It’s like the whole thing of drugs or no drugs making you more creative – neither is a guarantee.”

On Schlagenheim, Black Midi’s technical skill allows them to move through their innumerable ideas extremely quickly and fluidly. Throughout, I’m reminded more of the compositional style of electronic producers like Blanck Mass and Aphex Twin than the milieu of punk and garage bands from which they’ve emerged.

Simpson agrees with this. “Absolutely. We’re obviously a guitar band, but we don’t look at it like that. Don’t necessarily label things – the moment you do that, there’s only so far you can go. It’s the same with what we’re influenced by.”

“I don’t know if we’d go full Kraftwerk though, and ditch our instruments completely,” says Greep. “We need more control. But maybe for a couple of tunes, you never know…”