What exactly happened in Weisfeld's past in Body and Soul?
Weisfield is of course the first piano teacher of Claude who is instrumental in recognising and nurturing his talent and setting him on the road to fame and stardom. In a sense, he becomes a substitute father for Claude, almost adopting him because of his own lack of a family. We can see that the relationship the two characters form is reminiscent of a father-son relationship, and Weisfield remains one of the most important influences on Claude thorugh the entire text.
Weisfield left Poland after his family was killed by a bombing in 1939. He is a Polish Jew, and so had to flee Europe, and therefore went to New York to try and salvage some kind of new life for himself after the death and destruction he experienced in Europe. However, it is clear that the past still exerts an incredible influence on him, as shown by the way that he is haunted by dreams of his family and what happened to them. It is interesting that Weisfield only tells Claude about what happened to him on his deathbed. He manages to keep his past and present strictly compartmentalised, as the way in which he prevents Claude from entering his apartment, containing lots of photos of his family, demonstrates.