Friedrich began his career at the Komische Oper in East Berlin in 1953, where he was a student and assistant of Walter Felsenstein, and directed his early productions.
He was known for his Wagner productions, and first became known internationally with his controversial 1972 Tannhäuser at Bayreuth.
From 1981 until he death from cancer on 12 December 2000, aged seventy, he was general director at Deutsche Oper Berlin, where he was known for his artistically controversial and uncompromising leadership.
Hans Zehetmair, who was Bavaria's culture minister at the time of Friedrich's death, referred to Friedrich, who was active also as a teacher, as 'both a creator and a facilitator'. Friedrich's final production, Gian Carlo Menotti's Amahl and the Night Visitors, took place just a few days before his death, and although too ill to attend, Friedrich, in the words of Christoph Stölzl, Berlin's then chief culture official, 'was able to make this children's opera a wonderful, fantasy-filled farewell gift'.