Mario Caldato Jr. is a musician known as Mario C, the Brazilian-American producer and engineer who helped create the radical and explosive sound of the Beastie Boys. He was introduced to the Beastie Boys in LA in the late '80s, and engineered the group's classic second album _Paul’s Boutique_; he went on to coproduce and engineer their multiplatinum classics _Check Your Head_, _Ill Communication_ and _Hello Nasty_. His work became so crucial to the Beastie Boys sound that he’s regularly name-checked in their verses. Besides his work with the trio, Mario C has collaborated with dozens of artists from all over the world, including Beck, Jack Johnson, Bebel Gilberto, Money Mark, Yoko Ono, Seu Jorge and Manu Chao.