From: Marlon Brando (with Robert Lindsey), Brando: Songs My Mother Taught Me, New York: Random House (1994), page 79:
Hollywood was always a Jewish community; it was started by Jews and to this day is run largely by Jews. But for a long time it was venomously anti-Semitic in a perverse way, especially before the war, when Jewish performers had to disguise their Jewishness if they wanted a job. These actors were frightened, and understandably so. When I was breaking into acting, I constantly heard about agents submitting an actor or actress for a part, taking them to the theater for a reading and afterward hearing the producer say, “Terrific. Thank you very much. We’ll call you.”
After the actor was gone, the agent would ask, “Well, Al, what did you think?”
“Great,” the producer would say, “He was terrific, but he’s too Jewish.”
If you “looked Jewish,” you didn’t get a part and couldn’t make a living. You had to look like Kirk Douglas, Tony Curtis, Paul Muni or Paulette Goddard and change your name. They were Jews, but didn’t “look Jewish” and employed the camouflage of non-Jewish names. Hence Julius Garfinkle became John Garfield, Marion Levy became Paulette Goddard, Emmanuel Goldenberg became Edward G. Robinson and Muni Weisenfreund became Paul Muni.
(Note: Paulette Goddard, born Marion Levy, was the daughter of a Jewish man and an Episcopalian woman.)