The last master student of Hanns Eisler, he composed music in many genres, including works for the stage.

Katzer was one of the pioneers of electronic new music in the German Democratic Republic and the founder of the first electronic-music studio in the GDR.

He held leading positions in music organisations, first in the East (Akademie der Künste der DDR), then in the united Germany (Academy of Arts, Berlin, and Deutscher Musikrat), and received many awards, including the Art Prize of the German Democratic Republic, the National Prize of the German Democratic Republic, the Order of Merit of the Federal Republic of Germany, and the German Music Authors' Prize.

[2] Katzer's earlier works owe a great deal to the music of Béla Bartók, Igor Stravinsky, and his teacher, Hanns Eisler.

In the late 1960s he came under the influence of Witold Lutosławski and Bernd Alois Zimmermann, departing from conventional tonality and forms.