Returns from American captivity. First contact with jazz there. Autodidactic studies in the following years.
1921
Composition lessons with Bernhard Sekles, piano with Willy Renner Frankfurt/Main.
1922
First performances, Heiß joins the Freie Gesellschaft für Musik
1923–1925
Herman Heiß becomes increasingly involved with twelve-tone music. Acquaintance with Josef Matthias Hauer. Studies with Hauer in Vienna.
1925/1926
Composition E-F#-D for piano, a defining and fundamental work for Heiß.
1926/27
Piano lessons with Alfred Hoehn in Frankfurt/Main.
1928–1933
Music teacher on Spiekeroog
1933–1941
Freelance composer in Berlin, propaganda music. Commissioned work for the 1936 Olympics "Das Jahresrad", performance suppressed, 1937 the fairy-tale opera "Prinzessin Filigran".
1942
Return to Darmstadt.
1944
Air raid on Darmstadt, many works are burnt. Hermann Heiß moves to Vienna and teaches at the Music School, City of Vienna
1946
Darmstadt. Musical and cultural engagement in the Ottenheimer household. Lecturer in composition at the Darmstadt Summer Courses.
1948
Georg Büchner Prize. Teacher of composition at the Städtische Akademie für Tonkunst in Darmstadt.
1951
First interest in electronic sound generation.
1952–1954
Experiments in the (N)WDR studio in Cologne. First electronic works are created: 1953 "Electronic Studies", 1954 "Electronic Discontinuum."
1955
Head of the "Studio for Electronic Composition" at the Kranichstein Music Institute.
1956/57
Development of the Heiß-Vollmer tape recorder for more rational tape editing.
12.07.1957
Foundation of the "Studio for Electronic Composition Hermann Heiß Darmstadt" in the annex of the Städtische Akademie für Tonkunst in Darmstadt. In the following years until his death, numerous electronic compositions and commissioned music for stage, radio, film and television are created in this studio.
ab 1957
National and international lectures on electronic music.
1958
Goethe Plaque of the State of Hesse, Johann Heinrich Merck Honour of the City of Darmstadt.