Kyle Richard Gass (born July 14, 1960), also known as KG or Kage, is an American rock musician, singer-songwriter and actor. He fronts the comedy rock band Tenacious D alongside longtime friend Jack Black. He also has his own super-group called The Kyle Gass Band and he was also a member of the band Trainwreck before it split up 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 Jack Black's son.