How do you keep a band interesting after ten years? It’s a question Slow Club’s Charles Watson and Rebecca Taylor must have asked themselves as they started work on their fourth album. From the cute indie-folk of their 2009 debut Yeah So, to the wonky-pop of its follow up Paradise, two years later, to the sophisticated, polished soul of 2014’s Complete Surrender, this is a band that have never stood still, going out of their way to present a new version of themselves on every release, while maintaining the spirit, the warmth and the chemistry that has marked their music since they formed in 2006.

Yet Slow Club 2016 are a very different proposition to the indie duo of a decade ago, who carried makeshift percussion rigs around their native Sheffield in parents’ cars, sang everything in close harmony and wrote from a shared perspective. The pair live in different parts of the country now, and work in very different ways. Charles is in London. Rebecca lives in Margate, throwing herself into the artistic community there. Charles writes obliquely, using short stories and found narratives to transmit his ideas, while Rebecca’s lyrics are starker and more personal, channelling her heartbreak and happiness in a very direct way. How do you bring two distinct styles, two distinct lives, back together and make them feel like the same band?

Apparently, you send them to Richmond, Virginia for a week.

Make no mistake, One Day All Of This Won't Matter Anymore, the duo’s fourth album, is the best thing Slow Club have ever done - their warmest, their most classic sounding, their most cohesive album yet, smoothing those two disparate approaches with a woozy, late-night, candlelit vibe that softens the pop hooks and makes choruses glow.

The secret weapon is producer Matthew E. White, the master of Southern-gothic folk, whose in-house band at Richmond’s Spacebomb Studios provided the consistency and tone the album required. On previous records the duo would play most of the instruments themselves, aided by occasional friends. Here they handed their songs to Spacebomb’s core unit: guitarist Alan Parker, drummer Pinson Chanselle, bassist Cameron Ralston and keyboard player Daniel Clarke, encouraging them to develop their parts and help arrange the music. Almost every track was played live in the studio, allowing the long-established session band’s natural chemistry to augment Charles and Rebecca’s, with the double advantage of recording being very effective, and also comparatively quick.

“It desperately needed that.” says Rebecca, “We weren't as on the same page about what we wanted this time, we were sort-of blindly going into it. We needed someone to come in and take control. Going in there with those guys leant itself to that. It was perfect.”

It was a completely new way of working for the pair, recalling the great house-bands of the 60s and 70s, like Muscle Shoals’ Swampers or Phil Spector’s Wrecking Crew. “It felt old school in the sense that we were the writers and Spacebomb were the players” says Charles.

“It's great. It's taken us ten years to say ‘What if, right, we get everyone in the same room, and we have the same sound, and we get people who are really, really good to play it?’ Now we've figured it out.” says Rebecca.

The usual tensions of recording dissipated under the calm, laid back, familial atmosphere of camaraderie and creativity White and his band created.

“There were four players in the room: drums, bass, guitar, keys, so a bunch of people in the studio. I think that's why we had such a laugh.” says Charles, “Normally it's just the two of us and whoever we're working with. We might both be a bit knackered, or one of us is more excited about something than the other, but here there was this constant energy because there was always four or five of these guys, and they'd hear something and have this way of going ‘Oh daaaaamn’.”

“It was really funny because we're so British and cynical, and we don't vibe but they'd be, like, ‘Mmmm!’” says Rebecca.

“Mmmmm!” is a good way of putting it. “Daaaaaaamn” even more so. One Day All Of This Won't Matter Anymore is a hugely satisfying listening experience, dark but not downbeat, old-school without sounding dated, an album of great feel. You can understand why words like “vibe” were being thrown around the studio.

“To my mind it's warm,” says Rebecca, “there's this kind of unspoken finesse you get from these guys playing in a room all at once. It's sexy, and downbeat and cruising and dark. Not dark, like a mood, but candlelit. Where-as the last one was spotlights. I still managed to get a bit of spotlight in here, but it's mostly candles. We're getting on a bit, aren't we? We want everything to be warm, and nice, and have a high thread count. I spent £190 on sheets the other day. Don't print that, my Mum will be livid.”

“It’s really slow” says Charles, “I have a tendency to go really slow on everything and it always gets a bit sped up, but for the first time everything on the record is slower than the demos.”

“I think it's really fucking brave to go slow”, agrees Rebecca, “there's a confidence in it that, left unattended, we've always shied away from. I'm really proud of that.”

All this warmth, of all this chemistry, of all this slowness pays off. One Day All Of This Won't Matter Anymore is a late night record. It’s atmospheric and comforting (that’ll be Rebecca’s high thread count) and languid, but never boring. Slow, it might be, but that never feels like a bad thing. Opening track ‘Where The Light Gets Lost’ pulls its drifting, six-note guitar riff out of the air and it feels like waking from a deep sleep. Ten years ago ‘In Waves’ shuffling chord sequence would have been delivered at twice the speed with five times the amount of words, but here bathes itself in lap-steel guitar and takes its time, Rebecca’s vocal all space and wistfulness.

Wistfulness and acceptance are very much themes here. On ‘Come On Poet’, a clear highlight, Rebecca, giving one of her best-ever vocal performances, sings about “a chronic impatience, sufferer waiting for time to heal… Babies taking their lead from elders who still don’t know anything,” while Charles’s Silver Morning is about “a guy who won once and lost it all”.

If Complete Surrender was something of a breakup album One Day All Of This Won’t Matter Anymore is about learning that, eventually, you have to accept responsibility for your own life - never an easy thing.

“I didn't write anything for ages because it was all just so self-centred and 'God aren't I awful'” explains Rebecca, “I'm so jealous of how Charles can totally remove himself in songs, I did a little of that, but ultimately I had to go with what was coming out of me, and talk myself into using it. I've lived a thousand lives since that last break up, I've also done a lot of looking into myself and sort of building back what had been really fucking broken down. I feel like I'm still at the beginning of really healing and moving on, and becoming someone who isn't a quivering wreck. I'm my own biggest problem now. Which is just as hard.”

By contrast Charles songwriting style has become less confessional, and more oblique. “I’ve started work on a collection of short stories called 'Ike Jime Spike'”. He explains. “The Ike Jime Spike is basically a long screwdriver used by anglers to kill fish quickly and painlessly, but it struck me that it’s more about the humans suffering and seems like a strange thing. In the stories I wanted to explore the relationship between man and nature. Not all my lyrics are directly linked to this theme but I tried to occupy this space when writing. It became easier to say harder things this way.”

If all of this seems a little introspective, or in Charles’ case maybe a little intellectual, then don’t worry. At their heart Slow Club are still a pop band and One Day... contains some of the best melodies they’ve yet created. The duo’s knack for writing hooks and melody has, if anything, become stronger. There are choruses here you instantly feel you’ve known your whole life, like ‘Ancient Rolling Seas’ timeless, reassuring refrain of “I’ll always be by your side”, or ‘Champion’’s Dolly Parton via-Linda Ronstadt anthem of self-celebration through the darkest times. Perhaps best of all are a pair of songs to be found at the top of what traditionalists would call “side 2”- Rebecca Casanova, a slice of widescreen, four-to-the-floor pop that recalls soft-rock giants Fleetwood Mac in the way it channels heartbreak onto the dancefloor, and Tattoo Of The King, a Charles Watson tale that takes Neil Young and the Doobie Brothers to the disco. Neither sound like anything Slow Club have done before, while still somehow sounding like Slow Club always have. And if that seems like a contradiction, like two ideas saying something different but working together, well that’s Slow Club 2016 through and through.