Macklemore: 'I don't have moderation when using drugs and alcohol. It was hurting my life'

The next Vanilla Ice or the next Eminem? Macklemore doesn't have a record contract – but he does have the UK's biggest-selling single of the year. And it's about charity shops. Only one thing's sure for now: Macklemore and his musical partner Ryan Lewis are going to do this their way.

Ben Haggerty, better known by his rap alias Macklemore, has just hit the big time. You may not recognise his name yet, but by the end of the summer you will, and if you've ever heard his number-one hit "Thrift Shop", a high-octane tongue-in-cheek ode to charity shopping, chances are that its ferociously catchy chorus is still looping round inside your head.

Macklemore isn't giving interviews right now, but with "Thrift Shop" riding high as the UK's biggest-selling single of 2013, its follow-up "Can't Hold Us" currently in the top five, and a sold-out gig in London next week, he has reluctantly agreed to just this one…

Macklemore is learning the hard way that his new-found fame comes with baggage, and within minutes of entering his world, the constant interruptions and impositions from eager fans as he strolls the streets of New York ("I'm sorry that this was kinda a chaotic interview") become clear.

"Your privacy isn't the same, walking down the street isn't the same," he says. "I don't think you really have an idea what that's like until you're with your girl and you can't go anywhere without people taking a bunch of pictures. It's been an adjustment period, but I'm figuring ways around it. I'm wearing more hats and sunglasses out in public, ha ha."

It's not just the lack of privacy getting to him. Since "Thrift Shop" took off, Macklemore's US college tour (which was scheduled before the madness) has mushroomed into a non-stop, no-end-in-sight, flight-hopping series of gigs and TV appearances, to be followed by a 10-country world tour. "You know, we didn't really schedule this [college] tour thinking that there would be so many shows this year. So there has been very little sleep, lots of travelling, and it just wears you down. I've been home like four times since last fall. So it's, um, challenging."

The fame may be new, but 29-year-old Macklemore isn't. He started rapping at 15, and put out his first mixtape (the rap equivalent of a demo), "Open Your Eyes", in 2000 under the name Professor Macklemore. He soon became a regular face on Seattle's close-knit hip-hop scene, and built up a loyal local following. This, in spite of being a white kid from a privileged background ("I grew up on Capitol Hill with two parents and two cars/ They had a beautiful marriage, we even had a swing set in our yard", he rapped in "Claiming the City", in 2005).

But just as his career was just getting going, Macklemore started drinking and dabbling in drugs. Unlike some public figures, he has been open about his troubles: "I don't have moderation when using drugs and alcohol. It got to the point where it was hurting my life, my potential."

In 2008, following an intervention from his father, he entered rehab and has been sober (save for a slip-up documented in recent song "Starting Over") ever since.

On a mission to rediscover his musical voice, in late 2008 he started working with his now full-time producer and business partner, 25-year-old Ryan Lewis. Lewis explains that, in true underground style, the pair met on MySpace. "I had 'friend-requested' Ben after hearing one of his mixtapes and he responded by sending me a message about a beat. Not long after, we met at my parents' house and became friends." For the first few years of that friendship, Lewis worked mainly as Macklemore's photographer, but eventually the pair started making music together. The result, in 2010, was a seven-song EP called "VS (Redux)".

The Heist (which reached number one in the iTunes chart within hours of being released), is the duo's first studio album together – but though it has now sold more than half-a-million copies, the real star of the show is "Thrift Shop", a tune so soul-liftingly cheerful that it should be renamed "The Pringle Song", because it's almost impossible to listen to just once.

The single's global success (more than 2 million sales and number one in nine countries from the US to New Zealand to the UK) has, says Macklemore, "been intense. It's been a big life change. You know, this is what you dream of. When we were making The Heist I never thought it would get nearly this big, so I feel an immense sense of gratitude that people are connecting with the music as they are."

They are sentiments echoed by Lewis. "To see The Heist go this big is astonishing. Not because I don't believe we made great music or a great album – it's just so far beyond what a good album does [in terms of sales] in 2013 and it's a lot to wrap your head around. To do 78,000 [in the first week] was crazy."

Yet, while the accolades and bookings may have come in thick and fast, after years of hard graft and small-scale recognition, they are not letting themselves get too carried away. After his performance at the MTV Movie Awards, Macklemore tweeted: "I still feel like they let an underground rapper on TV… I don't think that will ever change." Is that still how he feels? "I mean, I know I'm not an underground rapper at this point at all… but, you know, I'm always gonna feel like that cos that's where I've come from."

Although "Thrift Shop" has proven Macklemore's breakthrough, its blithe spirit belies a serious artist with serious issues on his mind. His single "Same Love", for example, is an anthem to same-sex marriage. This call for equality isn't just attention-grabbing bandwagonning; with two gay uncles (his dad's brothers) and a gay godfather, this is an issue close to Macklemore's heart. Were his uncles shocked that their rapping nephew was making such a strong public statement on their behalf? "I was really nervous to play it for them. It's obviously a very personal song, and I didn't want to cross any boundaries in terms of their privacy. But we actually ended up taking a picture of them and using it as the cover art for the single. I wanted the art to reflect how personal the song was, and they are a big reason why I'm so passionate about the issue."

In the realm of hip-hop, often criticised for its obsession with material wealth and rampant homophobia, charity shopping and gay marriage are highly unusual subject matters to say the least. So does Macklemore see it as his mission to change the genre from the inside – or is he just rapping about what he knows? "I'm always trying to push the margins. I wanna be an artist that writes songs that are different; I don't wanna write the same song that everyone else is writing. I wanna challenge myself, I wanna challenge society, and I wanna be the best version of myself, and the way I can do that is by expressing and talking about concepts that no one else will, that people are afraid to address. I wanna be able to talk about those openly and honestly and figure myself out and help those who listen to the records figure them out."

His refreshing approach couldn't be more timely. Not only is same-sex marriage the big political debate dominating America right now, but last year R'n'B sensation Frank Ocean shocked the hip-hop world when he came out. And it seems that now the barriers are starting to break down, the fight for equality is gaining momentum. Earlier this month basketball player Jason Collins made history by becoming the first openly gay professional American sports star, and just a few days later rap legend Snoop Lion (formerly Snoop Dogg) made a sea-change and came out in support of the LGBT community.

Macklemore isn't just changing the music scene with his lyrics, though. Because in spite of all their success, Macklemore and Lewis are still unsigned. To put this into perspective, they are the first unsigned artists to reach number one in the US Billboard chart in more than a decade.

"It's been a challenge to get any sort of media behind what we do," admits the rapper. Yet Macklemore is deeply passionate about his independence; his song "Jimmy Iovine" (named after the influential American music producer) ends with the line, "Rather be a starving artist than succeed at getting fucked."

In fact, their independent spirit provides the very meaning behind their album's name – Macklemore and Lewis taking their fame and success by force, not waiting around for someone else to bestow it on them. In the world of music – controlled by middle-aged white men in remote offices and given away on prime-time TV by the likes of Simon Cowell – it's a defiant message, and their success has undoubtedly ruffled the major labels – if they can do it, what's stopping other artists coming up and hitting the big time under their own steam?

The fact that the duo remain unsigned doesn't mean that deals haven't been put on the table, however; in fact, Macklemore and Lewis have been approached by most of the major labels. "We weren't offered crazy deals until after The Heist was successful," reveals Lewis. "Before it came out, we got offered shitty deals that were pretty easy to recognise as being poor offers."

Another challenge to the scene: their race. Because as you might have noticed from the portrait on the previous spread, Macklemore is white. That's right, the music sensation of the year is an unsigned, white, hip-hop phenomenon who raps about charity shopping and same-sex marriage. And as you'd expect from an artist with Macklemore's approach, his skin colour is not a subject he shies from. In songs such as "A Wake" and "White Privilege", he tackles the issue head on.

"Yeah, it's always gonna be an issue," he says. "You know, I'm a white rapper. I'm gonna get compared to other people. It is who I am." When it comes to inevitable comparisons with white rappers past – namely Vanilla Ice and Eminem – he's philosophical. "We're human beings, we look at something or somebody and we compare them to what we know and how we can identify them with somebody else. We compare everything in society, so I would expect people to compare me. You know, I think there's times when it makes it harder to be a credible artist, but hopefully the music can speak for itself."

Macklemore isn't all solemn contemplation and angst, though – if nothing else, the video for "Thrift Shop" (approaching 300 million YouTube hits) proves he has a playful and more accessible side – which is where his mass appeal lies. Take his fashion tastes: his penchant for gargantuan faux-fur coats, suede-tasselled jackets, matador-style capes and even the occasional onesie have earned him nearly as many accolades as his music, with the cultural bellwether that is MTV calling him "devastatingly fly".

"I don't have a stylist. I just love fashion, I've always loved it," he tells me. "It's kind of the same thing with my music. I don't wanna dress like every other rapper, I wanna be creative, I wanna be original, be true to who I am."

So what can we expect from Macklemore in the future? Will he traverse the rocky path of fame, stay sober, continue to break down barriers and change the world one rap at a time? The signs look good. He's built up a close-knit team around him; his ever-calm and entrepreneurial collaborator Lewis, his fiancée Tricia Davis, who directs their videos and handles merchandising, and his motley crew of musicians and singers mean he has a strong support network with him at all times. Then there's his ever-growing fan base (who go by the name of the Shark Face Gang), which is sure to expand and strengthen following his first major world tour, which kicks off in London this September.

As for the big question which must be on the minds of all those at the top of the music industry: will the global phenomenon that is Macklemore and Lewis ever sign with a major label? "It would," says the rapper, "have to be the right deal. And to be perfectly honest with you, I doubt that deal exists."

'The Heist' is out now. Macklemore and Ryan Lewis play Radio 1's Big Weekend on 26 May and headline the Shepherd's Bush Empire in London on 27 May