Not referring to the internationally famous pop icon, of course. I have heard beer aficionados talk about someone named Michael Jackson, and it's clear that be played an important part in the modern beer world. Who was he, and what were those contributions?
He was an English author who was a noted expert on beer and whiskey, and he wrote a number of books on beer, probably most famously The World Guide to Beer.
To add some information, he was known as the "Beer Hunter". He would travel around the world in the pursuit of new beers. Unfortunately he died in 2007. Wikipedia has quite a lot more info about his life if you are interested.
His website, which is called Beer Hunter, contains parts of his work and is accessible here