Rick Rubin, producer and founder of Def jam Records. He has worked with artists such as Red Hot Chili Peppers, Metallica, Slayer, Nine Inch Nails, Weezer, Johnny Cash, LL Cool J, Slipknot, Aerosmith, Audioslave, Tom Petty, System of a Down, Linkin Park, Mick Jagger, The Dixie Chicks, Beastie Boys, Danzig, and Jay-Z. Basically, he’s a big deal in the music business.