That same year he fulfilled his duty for the Reichsarbeitsdienst and spent late 1937–early 1938 studying pedagogy at the Hochschule für Lehrerausbildung (lit.
In the 1960s, he earned more success as a composer, including a second scholarship to the Villa Massimo in 1963, and a fellowship in the Academy of Arts, Berlin); especially after his opera Die Soldaten premiered in 1965.
The composer's depression led to an emotional crisis, which was compounded by a quickly deteriorating eye problem.
[further explanation needed] On 10 August 1970, Zimmermann committed suicide at his home in Königsdorf near Cologne, five days after completing the score of his last composition, Ich wandte mich und sah an alles Unrecht das geschah unter der Sonne.
In his own compositional growth, he took his place in the progression of new music, from which the German composers were mostly separated during the Nazi regime.
He began writing works in the neoclassical style, continued with free atonality and twelve-tone music and eventually arrived at serialism (in 1956).
Zimmermann's use of this technique ranged from the embedding of individual musical quotes (seen somewhat in his orchestral work Photoptosis) to pieces that are built entirely as a collage (the ballet Musique pour les soupers du Roi Ubu).