In 1944 he was drafted into military service and was briefly held as a prisoner of war of the American Army in Bavaria.
After the end of World War II, he met composer Karl Amadeus Hartmann who introduced him to the music of Igor Stravinsky, Béla Bartók, Anton Webern, Edgard Varèse, Charles Ives and Erik Satie.
In 1954 Paul Dessau took him to East Germany, where Bredemeyer became a master student of Rudolf Wagner-Régeny at the DDR Academy of Arts, Berlin.
His grave is at Cemetery Pankow III, where many renown German artists are buried.
His oeuvre includes more than 600 works (of which around 300 are for theatre, film and audio drama), many of which have still not been performed in concert.