They love a good cover, do The xx. Not in the ironic McFly-doing-I-Kissed-A-Girl-in-Jo-Wiley’s-hilarious-Live-Lounge sense of the word. Nor in a Mark-Ronson-defecating-brass-all-over-The-Smiths vein either. No, when The xx take on another’s creation they strip it to its bones; they expose its inner beauty.

Until we’d heard the band’s take on Aaliyah’s ‘Hot Like Fire’ (sitting on the B-side to new single ‘Crystalised’) we’d taken the fallen princess of RnB on nothing but face value. Mrs R Kelly was a well-connected voice of new soul, but she was still largely singing songs to sell records, not to emotionally reach listeners. ‘Hot Like Fire’ wasn’t a soundtrack to falling in love, but rather one for doing the rude to. The drum and bass-less version that this shy quartet have committed to tape changed all of that.

“I like to take a songs that’s really different to us and make it my own,” explains band co-leader Romy, almost in a whisper “so I liked Aaliyah because we’re not an RnB pop band.”

“I’m a big Aaliyah fan,” says second head-honcho Oliver, only slightly louder. “I’ve got an older sister, and, like with most older siblings, you steal their stuff. So I stole loads of my sister’s CDs – TLC and Aaliyah – so it’s something I’ve wanted to try for a while.”

If Romy’s personal aim was to make the track her own, she’s certainly succeeded. The transformation from slick hip-grinder to minimal, beautiful love note is quite astonishing. It follows on from the band unearthing hidden depths in Womack & Womack’s ‘Teardrops’ some twelve months ago. Admittedly, the 80s classic is quite the emotionally-charged soul pop hit in its original form, but less so in the incarnation that the band happened upon it – “Shamefully, we got if from the garage remix,” winces Oliver. Regardless, we’ve been hooked ever since.

Like Hillary Clinton forgiving Bill’s late nights in the office [insert crude and obvious orifice joke here], relations found in certain bands are strictly professional means to an end. Johnny Borrell’s is the only signature on Razorlight’s contract for example, with all other members taking home a salary that could never be big enough but is rumoured to rival the average Sainsbury’s pay out; the Val Kilmer doppelganger in The Killers is there because Brandon Flowers’ pretty little mush knows that he needs him. Bono is actually tolerated as inside joke between the rest of U2 these days, but you get the picture. The xx will forever be exempt from this group though, on account of its core forming at nursery school.

Oliver and Romy – the band’s duel singers, writers, and bassist and guitarist, respectively – are a pair that are as bashful and polite as each other. After christening our now-monthly club night last June, compliments of their set flustered the modest duo. As would any two 19-year olds that have lived in each other’s pockets since they were 3, they trust each other completely. When it comes to writing music together, they only sing the lyrics they pen themselves, and never voice their interpretations of what a song is about.

“Because we come at it from different angle, it’s never about the same thing,” explains Romy. “We’re never singing to each other. A lot of the songs have references about relationships, but because Ollie’s my best friend I’m never going to be singing, ‘Oh I miss you’ at him. For a lot of our songs we have our own interpretations of what they’re about. We’d never say ‘this is going to be our break up song.’”

At 16, when Oliver and Romy became band mates as well as best mates, they soon found a creative ally in another studying – and failing – music at their school. Baria [keys] was then “a big Distillers fan” and the three were left to their own devises, experimenting with the music department’s new multi-track recorder. James completed the lineup a year later to programme the band’s beats and recreate them onstage with his speedy fingertips bouncing over a series of tabletop pads.

Ducking into an east London pub on route to their first ever video shoot, all four members of the band are as softly spoken and courteous as when we first met. Oliver even mentions how much he enjoyed one of our rambling podcasts a few months back, quoting a libellous comment I’d made about Robert Kilroy Silk being a thief. And how The xx carry themselves is synonymous with the dulcet pop the make but cannot describe.

“We’re always described as ‘hoody-wearing’,” notes Romy “because we wear hoddies, but that’s because we’re cold. It’s not like we’re from an estate or anything. Most people our age wear hoodies. I’m still having a bit of trouble describing us, and what other artists we sound like. I don’t think we can be considered any one genre.”

“It’s strange,” says Oliver “because of our age we get urban quite a lot. And then people start mentioning… Skins.” The towering bassist grimaces, setting off a domino rally of similar facial expressions around the table. “A lot of it is just because of our age.”

That’s one of the struggles of the youth, I guess. If you’re a band made up of 19 and 20-year olds you’re going to be compared to the characters from desperate TV shows commissioned at the end of a meeting that was pencilled in the diary as ‘Hollyoaks with tits brainstorming session’. In true, The xx’s music is a far cry from Skins: less ‘Standing In The Way Of Control’, more a down tempo Metronomy on sedatives. The covers they’ve tackled have been a success, but the band’s original compositions are set to shatter hearts further.

Preceding an album that won’t be out until September is this month’s debut single, ‘Crystalised’. Featuring the hushed vocals of Oliver and Romy – which alternate before synchronising as if made to do so – it’s an emotive affair that we’ve already learned to expect from the band. And its creator’s reluctance to discuss its message shouldn’t be a surprise either.

“You said it better than me,” says Romy to Oliver.

“Did I? errm… I always struggle with explaining this…” comes the reply.

Romy: “You said it after my cousin ask, ‘so what is this song actually about?’ And you said it. You said…” Romy pushes her hands out as if in The Supreme, singing ‘Stop! In The Names Of Love’.

“What? say Oliver, grimacing once more through a smile. “I dunno… it’s pretty self-explanitory…”

Romy finally goes for it. “It’s about… if someone’s getting a bit keen, it’s like, ‘slow down.’” She does the hand gesture again, which suddenly makes a lot of sense.

Clearly, The xx are very private individuals. And, as history’s shown us time and time again, those not chasing the London Lite column inches often make the best and most personal music – Anthony Hegharty, Thom Yorke, Burial, and now The xx, to name just a few.

Any hype they’ve received doesn’t bother them – most notably, the band featuring in NME’s ‘Ones To Watch’ issue this year – because they remain oblivious to it. “I didn’t realise that there was much hype,” says Baria “Because our manager doesn’t tell us about any of that.” Oliver simply considers being written and talked about “a really big compliment”, and thinks little else of it. Success could of course change all that. Next we see The xx – after they’ve supported The Big Pink, been the surprise hit of the summer and delivered one of the year’s most beautiful albums – the free Reeboks they’ve recently wangled (“Freeboks,” as Oliver calls them) may have mutated into many ugly corporate endorsements as the band cross the road to avoid wretched mortals like myself, but I very much doubt it. There’s more chance of seeing them in Skins.