There was an unwritten rule when I was a kid. Icons and pop stars could never be Welsh. Growing up in drizzly, grey old Newport, I used to look to Manchester, to London, to the States – anywhere outside of my immediate environment really. Back then, the future ambassadors of 'Cool Cymru' would have been at school - flicking wadded up paper from the back of the classroom, having their heads flushed down the toilet, plotting respective futures out in exercise books and carvings on desks. Local history to me was a few brief lines on steel production, a page or two on the Chartists and a phone book sized book of footnotes on heavy drinking. Everything else, it seemed, was trivia.

In April '84, 'Wood Beez (Pray Like Aretha Franklin)' crackled over airwaves from Anglesey to Arizona like an alien radio transmission beamed out to an unsuspecting planet. A gleaming, chromium nugget molded by ultra-modernist studioheads, it heralded in three and a half minutes the dramatic, bravura transformation of a band called Scritti Politti. Formerly a DIY squat punk band, they were now a group doused in glinting pop sheen. Knowing little of their past, there was a single fact that mind-boggled me. That was that the band's frontman – Green Gartside, six foot something with impossible hair – hailed from my hometown.

"When I was in Newport and places east, north and west of there," says Gartside, taking time out from the studio where he has been tirelessly tuning bass drum samples, "there were no bands at all that I was aware of. I remember growing up with an interest in music but the very fact that no one from that bit of Wales had ever done it before meant that it couldn't be done. It was without precedent. The whole area was peculiarly bereft of pop."

That Green (née Paul Julian Strohmeyer) would become the first Welsh pop star of note was a triumph. That he'd transcend radicalised roots – pounding the South Wales streets selling communist newspapers, making agit records for the fledgling Rough Trade label like the scuffed up post-punk of 'Skank Bloc Bologna' – to eventually create a music so far removed from both the green, green grass of home and the boarded-up squats of NW1 was something far more spectacular. Sat in a roof garden five storeys above the permanent bustle of Ridley Road Market, Green ponders the inspiration for Scritti's rebirth (and the catalyst for a personnel change that made him the only permanent band member to this day) came about partly through heeding the empowering manifesto of a band just one small step ahead of his own.

"There was a band - The Desperate Bicycles - that came from around here [Dalston] and they were massively important to me. Their rallying cry was 'It's easy, it's cheap, go and do it'. Going to New York to make a record was neither easy or cheap - it was expensive and difficult - but it was the 'go and do it' part that was heeded. Once the license was given then the fact that it was going to be difficult or expensive didn't seem any reason not to do it. It was definitely going to be more interesting than staying in the Electric Ballroom playing with the same handful of bands that were all playing 'the new rock music'. That was Joy Division and Echo and the Bunnymen at one end and my contemporaries, and bands like The Pop Group at the other end. Both extremes of which - and all of the territory in between - I was bored to death of. I thought Jesus Christ, let's get out of here."

The mammoth musical shift – the sonic equivalent of switching from analogue to Hi Def – that the band underwent was partly triggered by the first of a series of knocks to Gartside's confidence that caused a retreat from the day-to-day.

"I became sick. I went back to Caerleon [just outside Newport, Wales] and I started listening to my sister's music for the first time. She had a lot of black music. Around that time my parents moved to Florida, and it was visiting there I first heard black radio – that's where I first heard 'the funk'. The System, Zapp… artists like that. There was a rapid change of influences combined with a disgust at big-I 'Indie' being born. It didn't take long to say, 'Fuck that, let's do this instead.'"

Gartside's decision to reshape the band's sound led to a break from everything around him, both stylistic and logistic. Former co-conspirators Tom Morley and Nial Jinks left the picture; David Gamson and Fred Maher entered. Rough Trade's Geoff Travis – the guiding hand for so many of the truly great artists of the post-punk era – encouraged new management and the move to a new label with the financial wherewithal to realise Green's ambition. No more live gigs, just painstakingly crafted records. The resultant LP, Cupid and Psyche 85, yielded a string of radio-slaying singles ('Wood Beez…', 'Absolute', 'The Word Girl' and 'Perfect Way') that segued fluently between ultra-slick robotised funk and meticulously constructed swoonsome lovers rock. Huge sales followed. To all intents and purposes – notably to kids like me – this version, the one versed perfectly in ultra-modern black music styles, was Scritti Politti year zero; prior recordings in a pre-internet age were the stuff of hearsay and legend. Not that those who knew the band prior to their resurrection were quite so willing to embrace the band's new direction.

"A lot of the people that had liked me during the Rough Trade years really didn't like me anymore." Gartside recalls with the sort of memory reserved for elephants and piqued rock stars. "It did lead to some funny record reviews though which I cherish still for some of the opprobrium that was heaped on me. One writer made a point of saying that if this is supposed to be soul singing, compared to Otis Redding I sounded like Violet Elizabeth Bott [the spoiled little girl in Just William played in the '70s TV version by Bonnie Langford who shrills 'I'm going to squeam and squeam and squeam!']. I thought that was hilarious on so many levels. Not that it matters now, but I think there were a bunch of people who seemed to miss the point entirely. I wasn't ever trying to emulate any of the vocabulary or mannerisms of R&B singing."

But while Scritti's critics scratched their heads just out of step of the record buying public, Green would always find himself siding up to the detractors.

"I've always felt more comfortable with the bad reviews than the good ones. Well, until I decided to stop reading them. I'm the kind of person that if I'm in a room with twenty people all saying, 'That's good' and there's one person saying, 'You know what, that sucks', I'll be going, 'He's right! I'm sure it does suck…' After any approval you'd get a little frisson that lasted twenty minutes from somebody saying something nice, then… That unleashes a lot of self-doubt that turns into self-loathing. I've found that a lot over the years. With those emotions comes the rapid retreat from wanting to do it at all. And that's what happened back in the 90s."

Following the release of Provision - Cupid and Psyche's follow up and a record complete with a gorgeous, wistful Miles Davis trumpet solo on the hit single 'Oh Patti (Don't Feel Sorry For Loverboy)' - nagging fears about his own place in the scheme of things led to a Green undergoing a further crisis of self-doubt that would make him retreat to childhood haunts.

"I went kind of nuts," he states baldly. "I ended up in hospital. I was not a well man. That was the decision made for me. So I retreated back to Usk in Wales. I'd always liked the place when I was a kid. I knew it was quiet and I knew it had some nice pubs. I just wanted to get away from everybody. So I did. I split up with my girlfriend, split from my management, split up with the musicians in the band, left the record labels and left my flat in Islington empty. I left everything there for years."

It's worth stressing at this point that even though he's talking about crippling depression, everything is delivered with a hugely endearing candour, even when recounting the circumstances that signalled not just the end of a massively successful studio project but the very real possibility of the early curtailment of his entire career.

"It sounds dramatic but it's really just where my little experiment with making Top 40 pop music left me. Unceremoniously dumped, 'There you go son!' Sat in Usk doing the few things I did when I lived there. I spent a vast amount of time listening to hip hop; I played darts and I drank in the local pubs and I walked through the country lanes. And I did that for years and years. I just didn't do anything else."

While retreating to his homeland, Green unwittingly stepped aligned himself with centuries of stereotypically Welsh emotional behaviour – something that's torn through the hearts and minds of some of the country's most revered actors, poets and musicians over the years, leading to self-destructive behaviour more often than not with disastrous results.

"There's a thing about the Welsh," Gartside muses, "and it usually comes up when talking to Welsh journalists. They'll say that they think when one talks about the lack of self-confidence - something that's been one's undoing for a long time – that that's a very Welsh thing, that sense of not feeling an entitlement to be doing this. A constant questioning of yourself: 'Who do you think you are?' I think that of myself a lot."

Luckily, the deep-rooted obsession with black music first sparked back in Wales just downriver from Usk kicked in again when the music of a quartet of genius East Coast hip hop producers threw Green a lifeline.

"At first when I'd open the door to the music room down there, the smell of flight cases, of studio gear and guitars was enough to make me feel physically ill. But eventually I got bored with being down there and I finally started working again because I wanted to be able to make beats. I'd been taking trips to London and Bristol to buy tons and tons of hip hop records. It was DJ Premier… him, Pete Rock, Easy Mo Bee, Large Professor. They each had their signature approaches to making beats. And I thought, 'Well, there's a bunch of equipment in that room…' And that's how I started making music again, by making beats. I made hundreds and hundreds. That coincided with my boredom peaking in Usk and my sister asking me if I'd take over her flat in Dalston."

Following a hiatus between releases which made the Stone Roses look positively impulsive, Anomie & Bonhomie emerged eleven years after Provision. Another case of Gartside effortlessly surfing the zeitgeist, the record flipped fluently between block party hip hop and swooning Bacharach-style string pieces. Although it didn't match the sales of Cupid and Psyche or Provision, it proved the catalyst in reacquainting Green with Geoff Travis.

"I ended up having a lot of fun making that record. It's the result of subconsciously absorbing and utilising the music around me. That sort of thing does take time. After the album came out, Geoff got in touch. I hadn't heard from him in years. He said, 'You've made a great record but no one's going to hear it.' He said why didn't I go back to him for help. So I did. For years, he'd come to my house and hear music. He bought me a studio and set me up with all the gear I needed at home. He liked the songs as they were; the stripped down, more personal thing. He said why not make a record like that. And if it's good enough for him, that's good enough for me."

White Bread Black Beer, Scritti's 2006's LP, proved rehabilitative for Gartside in numerous ways. A sleek, gorgeous and deeply personal sounding record that comes dappled with the beautiful, magic frailty of a mid-60s Brian Wilson orbiting Earth from the Mir space station, it sounds like the solo album that's been trapped inside him during each of the scenery or personnel shifts of the two decades. Although recognised as a one of the albums of the year by the good people on the Mercury panel, it stood little chance on the night when faced with the frenzied whirlwind engulfing the first Arctic Monkeys LP. The critical success of the record was enough to force Green out of retirement and onto stage for the first time in twenty odd years. He credits his current home of east London as providing the catalyst for that to happen as – fantastically – all of the people in his touring band were regulars in his local.

"They all came from the George (the pub with the best jukebox in east London). Alyssa, our bass player, was working behind the bar and had never been a bass player before. I knew each of the people I was talking to each independently liked music. They'd come into the pub and we'd occasionally talk about music so when it came to putting the band together I thought why not ask the people there. I had no idea how good they are but I knew they were nice people. And because they were nice people, that's why it finally became possible to play live. The affordability back then, five years or so ago, meant Dalston had a lot of smart people without very much money. Interesting people were moving in and that worked for me, being around smart people with very little money."

With the interview over, Green's brow noticeably unfurrows as he prepares to return to the studio to continue work on the follow up to White Bread, Black Beer, a project he jokingly describes as being "all over the fucking place". Although currently one hundred plus songs and four years late, you get the feeling that Green is at his most comfortable at this stage of the process, consumed by music and out of scrutiny of the public eye. As we prepare to part, one last thing occurs to me. What do you think Green the communist newspaper seller from south Wales would have made of the current political climate? He mulls the question over.

"I think I would have been disgusted that we hadn't had a socialist revolution and that capitalism had managed to be so tenaciously successful. I despair of my atomised and politically adrift self. I keep wishing I had the energy to get out and protest; head down the Town Hall and take the No Bullshit option. I went on the TUC rally back in March. I ended up going on my own as all the people in the pub the night before were saying, 'Yeah, we're coming!' And did they fuck! The whole time on it, I knew that the next week we'd be back to things being decimated and laid to waste all around us without any real fight. But there – in the moment – there was such a great feeling, I almost didn't want the thing to ever stop."

And with that he heads home - the man who laid the foundation stone for rock'n'roll's Welsh Assembly thirty years or so years back – ready to take on one hundred tracks of bass drums.

Still a little red on the inside, he's reassuringly the same Green he's always been.