Mark Ronson slopes into the lobby of his hotel on Park Lane in central London and croaks an apology for being late. The eye-wateringly well-connected producer/DJ/musician (from Amy Winehouse’s Back to Black to Bruno Mars’ Uptown Funk) was out last night with Queens of the Stone Age, the macho American rockers whose most recent album he produced and who had just played a sweltering show in London. “We went out for dinner and just celebrated,” says Ronson, his transatlantic drawl reduced to half-speed. “It was fun.” The 42-year-old is clearly monumentally hungover.

Yet he remains infuriatingly articulate, name-dropping with abandon (Quincy Jones, Miley Cyrus, Will Smith, all of whom he has recently worked with) and displaying ubergeek recall on a range of topics, from