He was close to the expressionist circle around Herwarth Walden and was active (together with George Antheil, Hanns Eisler, Philipp Jarnach, Stefan Wolpe, and Kurt Weill) in the music section of the November Group of Max Butting and Hans Heinz Stuckenschmidt.
In 1933, branded a "degenerate artist" by the Nazi regime, he left Germany and went to Strasbourg, Brussels, Paris, and London.
Until he became a Swiss citizen in 1954, he was not allowed to work in Switzerland, and relied on the support of wealthy patrons and his wife, the writer Aline Valangin.
During this time, he taught composition privately, was active in the ISCM, participated in Hermann Scherchen’s ‘Sessions d’études musicales et dramatiques’ in Strasbourg, and organized the International Twelve-Tone Music pre-conference in Osilina in 1949.
His students include Erik Bergman, Tauno Marttinen, Maurice Karkoff, Rodolfo Holzmann, Robert Suter, Einojuhani Rautavaara, Andree Aeschlimann Rochat, Rolf Liebermann and Hermann Meier.