'It's not directed at smokers, it's about how we live our lives. I know people that are in jail for the paths they've chosen, but they knew the risks all along.' As he speaks, Shameless waves an unlit ciggie around as if to emphasise the title of his debut album is less one-man health warning, more a reminder to get the most out of life.
Indeed, Smokers Die Younger is crammed full of life, from celebrating the good times on No Hats No Trainers, to Live Fast's call to get out and do something. Moreover, he is just as happy with guitars as beats, as on his near-duet with Rod Stewart on Everyday. Live, Shameless performs with his own four-piece group - The PaddyRagga Band.
'I love hip hop, but I've always listened to bands like Nirvana, The Clash and The Specials, too' Shameless explains. 'All those things I've grown up with, I've driven into my music. It's sad that you only have rock bands on the front of the NME, while urban music is being demonised.'
He acquired his varied inspirations in Leytonstone, East London, where a young Shameless was born and raised by his Irish mum, giving him a taste for the craic - and his stage name.
'My Irish relations are outspoken, open minded and very funny, so I feel lucky to know that side of my family. In Irish, James is Seamus so that's what they would call me and where the inspiration for my stage name came from. All my antics and behaviour have been very much shameless and I've never regretted anything.'
It wasn't the pipes that called Shameless, though, but New York & L.A. Hip Hop's rugged beats and the frantic rhythms of drum and bass. He got into rap when he was nine years old, yet only when jungle came along did he decide to have a go himself.
'I used to hang out with a lot of older guys and they gave me a tape of NWA, that spoke to me. I quickly got into the likes of Tupac and Talib Kweli from there. I started to emulate MCs on pirate radio, though I felt I had a lot more to say than you can manage over a drum and bass beat.'
Before he was picked up by All City Music (home to Sway, no less), Shameless hooked up with his childhood friends to make tunes, forging a loose brotherhood of vocalists, musicians and producers that grew into the Dat Sound collective. Also guesting on his album is none other than potty-mouthed solo star Plan B.
'East London's a hot part of town, with a lot of people tapping into music,' Shameless enthuses. 'It means I have access to a much wider variety of talent for what I want to do. Plan B went to school with a mate of mine and I just met him in the manor, so it was a natural progression to work together. His music's aggressive, but we do have a laugh.'
His own bootleg of the Arctic Monkeys' When The Sun Goes Down, meanwhile, was given Noel Gallagher's seal of approval when he raved to it at the Sheffield band's end of tour party. Really, though, Shameless is only going back to his roots, for as a teenager he played in punk bands himself. If he does offer any kind of prescription, it is live life to the full.