Conversation so far:
Where was Bobby Darin born?
Bobby Darin was born in the East Harlem neighborhood of New York City.
When did Bobby Darin's name change from Walden Robert Cassotto to Bobby Darin?
Robert Cassotto became Bobby Darin thanks to a take out restaurant sign; the letters M, A and N on the light-up sign MANDARIN were not working, leaving only DARIN.

Question: Who was his father?
Self-contained rewrite: Who was Bobby Darin's father?