Kyle Richard Gass (born July 14, 1960), also known as KG, is an American rock musician, singer-songwriter and actor. He is a member of the comedy rock band Tenacious D, winner of a Grammy Award for Best Metal Performance, alongside longtime friend Jack Black. He also has his own supergroup called Kyle Gass Band which he formed after the break-up of his first side-project, Trainwreck in 2011. In Tenacious D, Gass plays lead guitar and sings backup vocals, and also plays the role of Black's comic foil in most of their comedy routines. He is the godfather of Black's son.