Sixt Dietrich (Xistus Theodericus) was a German composer. Since at least 1504, Sixtus was a chorister at the Cathedral Choir in Konstanz (Constance), where he was released on August 21, 1508 at his own request. On September 23, 1509 went to the University of Freiburg, where he became friends with Boniface Amerbach. InFreiburg he became a teacher of music and choir boys in Latin and was ordained a deacon in 1519.