Setting the scene: How Flume broke out of Australia to conquer the world

Harley Streten looks disconcertingly relaxed as he ascends the stairs of his tour bus, the 24-year-old’s sun-kissed skin complemented by the bus’s tan upholstery and set off by a white baseball cap. Outside, members of the Flume crew labour industriously, doing what needs to be done before tonight’s sold-out show at London’s historic Roundhouse, but inside the enveloping neutral tones of the coach, all is golden. Nobody is more surprised about it than the man of the moment himself: “I was thinking to myself earlier, how come I’m so fucking relaxed?” he ponders, leaning back in his seat. In six hours he’s due on stage, the first gig since the finished version of his second album ‘Skin’ landed in the hands of his label earlier this week. Asked if that has something to do with the sudden attack of Zen, he nods. “I got the zip file of the record in my inbox, I put it into iTunes and was like, ‘Yes, it’s done’.” The relief spreads over his boyish features, palpable and potent.

It’s been four years since Flume blew up, but the aftershocks still resonate. His debut album, released on Australian independent Future Classic in 2012, was one of those organic hits that no panel presentation or PR strategy can magic into fruition. It marked him out as one of the last artists to slip through when the industry gatekeepers were out to lunch, working out how to monetise SoundCloud and music blogs while he was using both to get massive for free. How else to explain the success of an introverted kid from Australia, one whose languid sound grafted the alien textures and anti-structures of experimental hip hop onto – with a dextrous sleight of hand – melodic and accessible party pop? But however unlikely his breakthrough, the stats spoke for themselves: he went from being a nobody to industry hot property. Flume went gold in his home country, while he colonised the global pop and dance markets by translating his idiosyncratic vision into remixes for Lorde, Arcade Fire and Disclosure. Things, in short, got very weird. “If someone has success in music, their whole life gets completely flipped,” he reflects. “Not only physically, with touring, but mentally. You’re now important. Your status just goes up, and it changes your personality – it’s your life. It’s... awesome.” He laughs, perhaps a little stiffly.

Now things are about to flip out all over again. Streten is braced to deliver his hugely anticipated follow-up, ‘Skin’ – a record that, according to the law of second albums, didn’t come easy. “No kidding!” he exclaims. “I think it just psyches people out, it psyched me out,” he says, of the sudden pressure. Then there’s the massive tour that will see him criss-cross time zones like hotel lobbies, and while the unveiling of his new live show will have to wait until Coachella, tonight’s gig will be the first time his European fans will have heard the bulk of his new material. The lead single ‘Never Be Like You’ has already knocked Zayn Malik’s ‘Pillowtalk’ off the No 1 spot in Australia and won co-signs from Annie Mac, while another teaser, a piece of sub-zero hip hop, features red hot rapper Vince Staples. So, you know, the signs are good.

They’re especially good given that the whole thing started life as an experimental side-project. “It really has shocked me quite a lot,” he says, of how big Flume has become. Had things gone as expected, we would be talking about What So Not, the far more straight-forward house project that he founded with his friend Chris Emerson. Flume, by contrast, was for headphones. “It was very strange to see these beats – beats which I thought were really chilled – to see people dancing enthusiastically to them at festivals, while singing along – or attempting to,” he says of those early days.