Bastille's recording studio of choice is festooned with fairy lights and platinum discs and located behind a Tesco Express, at the foot of a housing estate in south London. It's unusual to find a band in any such location before midday but here Bastille are at 9am, having touched down at 4am after playing to 25,000 fans in South Africa.
"I will probably need a mid-afternoon nap," declares Bastille's 26-year-old frontman, songwriter and co-producer Dan Smith. "Like a small child."
The first time we met was a year ago, at last year's Brit awards. Smith was sitting on the same table as labelmates Professor Green and Naughty Boy; his seat was sandwiched between two label executives. He wasn't having the time of his life. "I think what I said to you that night was that I didn't particularly want to be there," he laughs. "I was there due to reasons outside my control. I was there alone, as well."
The four-piece had been on tour in Europe, and the label would only stump up the cash for Smith to fly back to London. But a lot can change in 12 months. Bastille's debut album – a grandiose, noirish and mostly guitar-free take on guitar pop – has sold more than half a million copies in the UK, and was last year's biggest digital LP. Their single Pompeii has hit the top 10 in over a dozen countries, with the album heading for 2m worldwide sales.
This year the entire band will attend the Brits ceremony, partly because they're due to perform, and partly because they're nominated for awards in four categories, including British Album of the Year and British Group.
"There's something to be said," Smith muses, "about how they wouldn't pay for us to all go last year, and this year we're nominated four times."
All told, this is not bad for a band that didn't appear on last year's BBC Sound of 2013 poll, or among last year's Brits Critics' Choice shortlist, and have somehow sidestepped the current assumption that British pop should appear via support from 1Xtra or The X Factor, and British alternative music should arrive via the painfully insular, tastemaker-approved east London circuit. Even so, it's unlikely Smith will be schmoozing it up at the awards do.
"Most of the trappings of being in a band I find completely humiliating," he says.
Such as?
"Let's caveat this with, 'We're the luckiest people in the world and it's the most ridiculous job that's not a job', but there are things like record store signings," he says. "You go to some massive record store and you sit behind a desk with an embarrassingly huge banner of yourself behind you. And they always, without fail, put the album on really loud."
More shy than blithe, Smith is also frustratingly modest, reluctant not to underplay his success. Of Pompeii currently bounding up the Billboard chart – and having recently passed the 1m sales barrier in the US – he says first that this scenario is "ridiculous", then that "it just shows the size of the country".
I find myself reassuring him that it's all right to be proud of doing well but that, it seems, just isn't his style. "Reading interviews with other people, I see them say: 'All I want is for our band to be massive', but it was never an ambition of ours to be in a band that's this big. That's so far from how my mind works that I find it puzzling. There's nothing wrong with being ambitious, but we're not."The more Smith talks about his role as reluctant pop star, the more the claustrophobic tone of Bastille's saturnine pop makes sense. One of the band's early promotional photos depicts Smith alone on some wasteland – Wimbledon Common, he explains – looking like he'd prefer to be anywhere else. When asked to describe what was going on in that photo, he pulls a face. "I just didn't want us to be in our photos or videos," he explains. "Not in an east London 'Ooh let's be anonymous' way, just because there were things I was uncomfortable with. So I'd try to push back."
He just looked a bit cold. "I was violently ill with glandular fever."
From what he says today, Smith's reluctance to go "the full Borrell" was a source of early anxiety for Bastille's label, Virgin, and it came up when he agreed to take part in some media training. "I had an hour right at the beginning, and it was very odd," he recalls. "The label were concerned that I didn't want to be in photos or videos, so it was just me chatting to this woman about why I didn't want to do that. I left, and I was like, 'What do I do in an interview?' But it was fine, because we didn't really do any."
The band have, indeed, done relatively little press. Their success has been building since the independent release of their first single Flaws/Icarus in 2011, and it was established on the live circuit, on the airwaves, and online. The word-of-mouth success was driven by their freely downloadable mixtape releases containing covers, remixes and original songs. "Someone recently said to us: 'The mixtapes were very clever, was that the label's idea?' Actually the label were completely against it; we were stealing and sampling illegally left, right and centre. The label said: 'We want nothing to do with this.' When it came to hosting the mixtapes, I had to register the website myself."
Bastille were one of a handful of acts played to within an inch of their lives by Radio 1 during 2013. Smith's keen to point out that Radio 1's support "isn't necessarily something that 'just happened'"; he talks about the three singles before Pompeii broke through, the touring, the early plays on specialist shows. Then the last of those singles, 2012's re-release of Flaws, was B-listed on Radio 1, and became a minor hit. "When Flaws went to No 21 we thought it was the most chart-bothering thing we'd ever do," Dan recalls. "We had a little party and started thinking about the next album."
But Bastille's reign of chart- botheration was just beginning. Like Haim and the 1975, also championed by Radio 1 last year, Bastille subsequently scored a No 1 album, as well as two top-three singles. Suddenly, Bastille had become worth the gamble Smith made a few years ago when he decided to give pop a go, deferring his masters degree in journalism.
Smith's enthusiasm for the noble art of journalism go to waste, I ask him to imagine that he is the journalist today, and that I am the singer in Bastille. What questions would he ask me?
"I don't know," he says, which isn't a great start, but at least I know he hasn't come into the interview with an agenda. I ask Smith if he (he) thinks I (he) would be interesting to interview, which unfortunately sounds like a preposterously circuitous way of asking something else.
"Am I boring?" Dan ponders. "Maybe I am. I don't know. I have no idea."
Some people, I say, do think that Bastille are boring, although these are also the sort of people who use phrases like "music for people who don't like music".
"Well," he declares, "that's fucking bullshit. I don't think we're boring at all." Remembering his unofficial status as pop's most reasonable frontman, he adds: "Though I'm going to say that, aren't I?"
The suggestion that Bastille's fans somehow aren't proper music fans is, understandably, particularly irksome. "That's incredibly, horrendously patronising. It comes from quite an elitist place, which is unfortunate. I know who buys our music: we have such a diverse fanbase. If you look on iTunes and look at 'People who bought this also bought' … well, I don't know what people expect the common thread to be, but it's not there."
Concluding his statement with some panache, he adds: "I think, also, fundamentally, we don't really give a shit."
Actually, iTunes suggests that Bastille fans also enjoy the music of Alt-J, Gabrielle Aplin, Bombay Bicycle Club, the Maccabees and Charlie from Busted, which isn't a mile off what one might expect, though Bastille's music is the most interesting of the lot. While any of the bands who filled Bastille-shaped holes in charts gone by – Keane, for instance – followed a tune-heavy path of least resistance, there's an enjoyably dark edge to Bastille, which begins to make sense when Smith admits that as a teen he was obsessed with Darren Aronofosky's film Requiem for a Dream. Bastille's most recent video featured corpses lipsynching to Corona's Rhythm of the Night; another hit was titled after unfortunate Twin Peaks character Laura Palmer.
Little surprise, perhaps, that Smith's equally larged-haired hero David Lynch got in touch with Bastille to remix one of his own tunes last year. Well, it was supposed to be a remix: by the time Smith had added his own vocals it ended up being more of a vigilante duet. "It was like handing in homework," he laughs. "Was it disrespectful that I'd crowbarred myself into his song?"
Lynch gave the remix his thumbs up, and further collaborations are underway. Bastille's first album was created in something of a bubble but the second is being recorded above the distant chime of Smith's phone ringing off the hook. He recorded with Sam Smith for his album, recently worked with Angel Haze for a future Bastille release, and is collaborating with rising young artist MNEK. There are also hints that Smith could become a regular hitmaker for other singers: he recently came close to selling a song to David Guetta ("Though there would never have been a question of me actually singing on a Guetta song"), and talks today about "a really interesting session, which I think will be quite fun", with an artist he refuses to name. (It's not Rihanna.)
His focus, however, remains with Bastille. "All our heads are in the next album," he says, adding that over Christmas he started five songs for the band's second album the same way he began the tracks that would form the first: alone, in a bedroom. The presence of more noticeable guitars in the band's recent live shows might suggest a move away from the idiosyncratic sound that made Bastille big in the first place. But Smith, whose self-consciousness as a frontman sits strangely alongside his unselfconsciousness as a musician, points out that of late he's actually been listening to "loads of R&B and more electronic music". If this also signals an abrupt change in direction, bear in mind that he also says Bastille's debut release was influenced by "hip-hop and Simon & Garfunkel", so the sonic direction of Bastille Mark 2 is hard to predict.
"I want to defy expectations," he says, and the slightest amount of light creeps through the armour of his self-declared lack of ambition. And while Dan may never want to be Bono, when he looks back over the achievements of the last 12 months he awards himself a rare pat on the back. "I think," he says, "we've had a really interesting year of slightly proving people wrong."
