Katzer was born as the son of a pastry chef. He finished his high school diploma at the boarding school Schloss Wendgräben (Möckern/Saxony-Anhalt). Between 1953 and 1959 he studied piano, music theory and composition with Rudolf Wagner-Régeny and Ruth Zechlin at the Hochschule für Musik in East Berlin. From 1957 to 1958 he studied with Karel Janá?ek at the Academy of Performing Arts in Prague. From 1961 to 1963 he was a master student of Hanns Eisler, Ruth Zechlin and Leo Spies at the German Academy of Arts in Berlin.
Since 1963 he was a freelance composer and musician in Berlin. From 1966 to 1967 he was music dramaturge on the Erich-Weinert-Ensemble of the NVA of the GDR. He collaborated with artists such as Johannes “Hannes” Bauer, Wolfgang Fuchs, Paul Lytton, Phil Minton, Ernst-Ludwig Petrowsky, Radu Malfatti, Phil Wachsmann and the Bläservereinigung Berlin.
In 1976 he stayed in the studio for electronic music in Bratislava and in 1977 in Bourges / France. In 1978 he was elected a member of the Academy of Arts in East Berlin. In 1982 he founded the Music Academy of the Arts affiliated studio for electroacoustic music, whose artistic director he was until 2005.
In 1986 he was a visiting professor at Michigan State University. In 1987 he was appointed professor and subsequently taught a master class in composition at the Academy of Arts. He was a member of the Academy of Arts Berlin-Brandenburg, the Free Academy of the Arts in Lipsia and the Academy of Electroacoustic Music in Bourges, France.
Until 1989 he was Vice President of the Association of Composers and Musicologists of the GDR. From 1988 to 1991 he was President of the German section of C.I.M.E. (International Association for Electroacoustic Music), 1990 President of the Music Council of the GDR and from 1990 to 2001 member of the board of the German Music Council.
Katzer's compositions include works for chamber ensembles, orchestral works, solo concerts, operas, ballets, puppet shows and oratorical works. His work also includes electroacoustic pieces, radio drama music, multimedia projects and projects with improvised music. New compositions have been published by Edition Gravis.
Katzer lived in Zeuthen near Berlin until his death.