Tyranny was born Joseph Gantic in San Antonio on January 1, 1945 to William and Eleanor Gantic. Later that year, after his birth father went missing in the Asian theater of World War II, he was adopted by Dorothy and Meyer Sheff of San Antonio and his name was changed to Robert Nathan. Tyranny was raised in the Lutheran church. He studied piano with Meta Hertwig and Rodney Hoare, and composition with Otto Wick and Frank Hughes.