Eating breakfast in a tiny cafe, at a glance, you wouldn't think Mark Ronson was currently among the most-listened to artists in the world.

His song Uptown Funk, featuring Bruno Mars, has spent five weeks at number one in the UK - stepping down briefly for X Factor winner Ben Haenow at Christmas - and with more than 2.5million plays on the likes of Spotify and Deezer, it's also the UK's most-streamed.

If you were at a party in December, it's likely the Prince-meets-The Gap Band track was played - and that goes for those living in Ireland, the US, Canada, Australia and Belgium too, where it also topped the charts.

Uptown Funk isn't hugely indicative of the album it comes from, Uptown Special, although the way it came about is perhaps typical of the way Ronson's fourth album was put together.

After his previous offering - the disappointing, disjointed Record Collection released in 2010 - he felt it was time to start thinking about what he'd do next. His day job, producing albums for other artists, including Duran Duran, Paul McCartney and Bruno Mars, was still going well, but Ronson feels that on his own, he can make the music he'd never be able to while working for, rather than with other artists.

"I DJ a lot of hip hop, so I'll be at festivals around the likes of Hudson Mohawke and people like that, and there are a lot of people like Joey Bada$$, Chance The Rapper and Action Bronson coming up, all these exciting guys, which made me think I should make a hip hop album," explains the 39-year-old, in his unmistakeable half-London, half-New York drawl.

"Then I thought, 'I'm nearly 40. I can't hang with those 24-year-olds'."

After that realisation, he had another - that his fourth album, whatever it was, had to be the best he'd ever made, if his career as an artist was to continue.

"The only way to do that," he says, "was to do the thing that I do really well, that maybe no one else does. So I had to think, 'What's my secret weapon, what's my superpower?'

"Looking back over the records I've done, the stuff that's worked the best is always live musicians, inspired by all my favourite black music from the Seventies, Eighties and Nineties, referencing the stuff I played in my DJ sets in New York when I was younger. Back then, it was disco classics, reggae, old and new hip hop and some house."

His first call was to Jeff Bhasker, co-writer and/or co-producer of some of the biggest songs of the past 15 years by the likes of Kanye West, Fun, Lana Del Rey, Alicia Keys, Taylor Swift and Beyonce. Ronson had asked Bhasker to work with him on Bruno Mars' Locked Out Of Heaven, not knowing the pair had previously been in an LA covers band together - until Mars was sacked by the bar who booked them.

"Imagine sacking Bruno Mars, the world's greatest performer," notes Ronson.

Pretty soon, he and Bhasker were putting down a blueprint for what would become Uptown Special, among the most important ideas being what Bhasker called 'Church Idol'.

Ronson tells the story doing an impression of a drunk Bhasker holding court in a bar, excitedly yelling his idea - but in a nutshell, they decided they'd drive to America's Deep South and check out the very best singing talent in church choirs, universities and bars.

"Even if we hadn't have found a singer, the trip would've been worth it," he says. "I've not been to that area before, but it's where all my favourite music comes from; gospel music that eventually turned into soul.

"Those churches were incredible, going through Memphis, stopping off at Sun Studios and Royal Studios, it was a real trip," he adds, referring to the Memphis studio used by Chuck Berry, Al Green, Ike & Tina Turner, Solomon Burke and The Staple Singers, among many, many others. "So that's where we made this album."

The pair visited Jackson, Mississippi, where they heard Keyone Starr sing for the first time. Within a few notes, Ronson knew he'd found the voice he'd been looking for, and approached her about possibly singing on his album.

"She had a slight scratchiness, or rasp, to her voice that I'm always looking for - Amy Winehouse had it, Lauryn Hill has it. It's grit. Keyone looked really cool, too, loads of attitude. I was convinced."

They didn't tell the singers initially what they were up to - " we didn't want them to think we were judging them, especially if it was in church, that's sort of sacrilegious".

"A few said they could go to a studio and test out for us, but they couldn't miss choir practice on Tuesdays and Thursdays. Church is everything to them, and they'd say unless they're singing for God, they just don't feel it, which was really heartening to hear, because it's the opposite of what people say when they go on TV in the UK to sing; they'll sing whatever they're given.

"Keyone gave us an inkling that she was special, and the first time in the studio on the microphone, she sounded perfect, so I said, 'Do you know what it's going to be like? If you come along for this ride, it's not all fun and limos and TV shows. It's a lot of travelling, getting up at 5am and being away from your family'. I was just trying to be real with her."

The young singer replied: "Are you kidding? Honey I can't wait to quit my job!"

A long process to this point, the rest of Uptown Special came together relatively easy, although Ronson did spend six or seven months of his time following Bruno Mars around the world while on tour, so he could record all the drum parts for Uptown Special.

Among the first things you hear on the album is a harmonica that sounds eerily like Stevie Wonder's distinctive playing.

"That's because it's him," beams Ronson, enthusiastically. "I knew I wanted him, but how do I ask my all-time favourite artist to be on my album?"

The idea wouldn't go away, so eventually Ronson wrote an email to Wonder's manager - and received a positive response.

The likes of Miike Snow's Andrew Wyatt and Tame Impala's Kevin Parker, who both offer crucial moments on the album, came a lot easier, from friendships forged while touring all over the world.

That leads Ronson to ponder his position as a producer, and his reputation.

"Being able to ask someone like Kevin from Tame Impala to fly from Australia to Memphis for a week is important," he says. "It does mean people just think I'm this facilitator that gets other people to make a record for him, and I can't shy away from that. I know that I'm good at creating a vibe where people feel nurtured and creative.

"But there's a disconnect between what people think I do, and what I actually do. It's important people know I write too.

"I wrote even more than I normally do on this record, and played a lot more. Being surrounded by this extended musical family means I challenge myself - Jeff Bhasker is intimidating, he's so talented," Ronson adds.

"But that's the challenge, raising your game. That's how you get better."

EXTRA TIME - MARK RONSON

:: Mark Ronson was born in London on September 4, 1975.

:: Back To Black, the album Ronson produced and co-wrote with Amy Winehouse, has sold around 20 million copies around the world.

:: He recently told The Guardian: "No one's ever going to compare to Amy because of the talent she had and the unique bond we had, that rapport, that energy in the studio."

:: Ronson was DJ at the wedding of Tom Cruise and Katie Holmes, although a strict contract forbids him from talking about it.

:: He is married to Josephine de La Baume, a French model, singer and actor he met on the set of one his videos.

:: Mark Ronson' s new album Uptown Special is out now