Nearly 4 years and 30 lbs. ago, I had the chance to help put together an event that involved Alan Parsons.
I could sit here all day trying to list this guy's credits, but I'll just mention a couple.
He engineered Pink Floyd's Dark Side of the Moon and also did engineering work on The Beatles' Abbey Road album. Two projects with reasonable importance in music history (understatement), but Parsons' resume goes much further. Read more about him here.