Pablo Casals
In 1921, he met and even played with Pablo Casals who was touring the United States. The latter encouraged him further studying in Europe which he did with Julius Klengel, Hugo Becker, Nadia Boulanger and Diran Alexanian; Pablo Casals remained however his most important mentor and they became lifelong friends. Eisenberg spent the years between 1926-1939 playing and teaching in Europe: