[2] He also dabbled as a stage director, including productions of Kurt Weill's Rise and Fall of the City of Mahagonny.
Heinsheimer supported the impoverished composer – whose leukemia contributed to increasingly poor health – through a conspiracy to channel funds disguised as record royalties.
He managed the publications of composers including Leonard Bernstein, Gian Carlo Menotti, and Samuel Barber, and also brought out Albert Schweitzer's edition of Bach's organ works.
[5] After his retirement in 1977, he contributed many articles to the supplement to first edition of the large German music encyclopedia, Die Musik in Geschichte und Gegenwart.
Also, in his retirement, he made many special contributions to the arts section (Feuilleton) of the Frankfurter Allgemeine Zeitung (FAZ).