I was disappointed that Jay-Z's memoir, Decoded, doesn't go into even more detail about his days in the New York crack cocaine business. As a half-Jewish philosophy graduate raised in Hampstead, I naturally consider myself a bit of an expert on the subject. I watch The Wire, of course; but I also listen to a tremendous amount of coke rap, a subgenre in which the everyday logistics of drug distribution are described with such repetitious attention to detail that it sometimes feels like taking a seat at a corporate training seminar. I've never smoked, sold or synthesised crack cocaine, so it's hard to say why coke rap is so important to me, but at this point I understand the mechanics of Jay-Z's former vocation considerably better than I understand, for instance, what my flatmate does all day in her marketing job.

And yet the truth is that my flatmate has more in common with Jay-Z than I do: in 2008, Jay-Z co-founded a marketing agency. He also has investments in streetwear, nightclubs, restaurants, hotels, beauty products and a basketball team. He isn't quite the richest rapper alive – according