You expect a swashbuckling dilettante, with great hair and killer patter. That, after all, is the face Mark Ronson presents to the world on Uptown Funk, the season's inescapable pop juggernaut.
Stood beside Bruno Mars in the video, he is indefatigably sharp, sporting a gleaming quiff and rock star mirrorshades. Where Mars huffs and puffs and works his hat, Ronson is effortlessly mysterious – ice cool amid the retro bustle.
So it's a surprise just how low-key a figure Ronson cuts in person. He is quietly-spoken and rather thoughtful – not at all the gent-about-town he is often taken for. Nor does he seem exactly ecstatic at Uptown Funk's success (100 million YouTube hits and counting, number one across Ireland, Britain and America). Recently turned 39, Ronson's been around long enough to appreciate success is fleeting – that it is our failures which define us as much as our breakthroughs.
"It feels great and it feels strange to have a huge hit," he says. "I love the song – that's the main thing. It's not some song I hated that just suddenly became popular. I love Uptown Funk and believe in it. At the same time, whether or not something becomes a hit is not up to you. All you can do is make it great."
Though Uptown Funk comes off as effortless – breezy swagger is arguably its winning quality – a world of toil and heartache went into the tune. It began as a groove, with Ronson playing bass and Bruno Mars on drums. They laid down 90 seconds of devastating rhythm, then ran out of ideas. On the drive home, Ronson couldn't stop listening to the recording – and yet was concerned as to where the song went next. Honestly, he was stumped.
"Everyone was just so excited. It was only a minute and a half. We knew it worked. However, as is often the case, it was difficult to get back to the vibe. If you try too hard, it can start to feel forced. "
He worried he might never finish Uptown Funk, grew so stressed he actually threw up."We did a lot of late nights. There were sleepless sessions. We worked on the song in Memphis, Toronto, London. It was like 'oh man, this sucks'. We had this magic one time and then it was gone. We thought it might not return."
The graft and anguish eventually paid off: somehow, Uptown Funk came together, as did the accompanying LP, Uptown Special – a retro tour de force with lyrics by cult novelist Michael Chabon and contributions from Stevie Wonder and Kevin Wilson of indie band Tame Impala.
For Ronson, Uptown Special is more than a hugely anticipated album. It marks a new chapter in his career, the first he has embarked on without Amy Winehouse, his dear friend and protege who died in 2011, at the tragic age of 27. Her death, he confesses, left him 'messed up': he couldn't sleep, drank to excess. Ronson has yet to visit the statue of Winehouse erected in north London. It would simply hurt too much. "I definitely miss her," he says. "I wish she was still around."
Ronson's first flush of fame arrived in the wake of Back To Black, Winehouse's breakout album from 2006. For a time he became notorious as something of a party-boy, with glamorous girlfriends and a penchant for the red carpet (today he is married, to model/actress Josephine de la Baume).
"I was going out too much," he nods. "If you are going out to clubs every night you can't be angry if people say that you go to clubs every night. There was an element of it being my first time at the rodeo. People were like 'hey do you want to come to this party, do you want free drinks?' I fell into the cliché for a minute: I don't necessarily regret it, though it would have been nice to not have been wasted through some of those experiences – playing Glastonbury and so forth. It's something you go through as you grow up, I guess."
Ronson's transatlantic accent attests to his unusual upbringing. He was born in London, to a socialite mother and a real estate and music mogul father. Following his parents' divorce, his mother married Mick Jones, guitarist with the rock group Foreigner and relocated to New York, where Ronson was partly raised (he attended super-swanky Collegiate School on the Upper East Side, alma mater to John F Kennedy Jr, David Duchovny and Buzzfeed founder Jon Steinberg). You wonder if growing up with a silver spoon has given him a fire in his belly - a determination to prove to the world he isn't a rich kid who came by his celebrity easily.
"I first made my name in hip hop clubs in New York," he shrugs. "Nobody knew or cared who my family was. It was only when my name started to crop up in the more tabloidy places that people paid notice. The fire in my belly comes from wanting to be the best – wanting to have the respect of my peers and to occasionally strike fear into them."
He exudes little of the entitlement associated with the super-wealthy. "I don't know anyone who is [outwardly] confident who is not a liar. Every musician I know, no matter how much they put on an act, has their insecurities. Whether your work is validated or not depends on what everyone else thinks of it. The only way I know something is really good if I'm playing it with someone in the room and I don't hear 500 things wrong and don't want to crawl under the sound desk."
It is a curious feature of Ronson's career that much of his best work has been with iconic female singers – Winehouse and also Lily Allen and Adele (who, as an unknown, lobbied hard for him work with her). He sometimes wonders where and how that chemistry developed and why, with Uptown Special, he is now working exclusively with male artists.
"All my initial success was with these amazing female vocalists – Lily, Adele, Amy Winehouse. I don't know if there's too much rhyme or reason to it. I grew up raised by my mother and two sisters. But I don't think it's actually that deep. You just like what you like at the time."
The album Uptown Special is out now.