Why is Bud an orphan?

Bud is an orphan because his biological father left his family before Bud was born, and his mother died when he was six years old. Bud's mother, Angela Janet Caldwell, is the daughter of a famous musician named Herman E. Calloway. Herman was very hard on his daughter and pushed her to graduate college when she didn't want to. She finally ran away from home to Flint, Michigan with a drummer from Herman's band. Curtis does not mention anything about Bud's biological father throughout the novel, but he more than likely left Angela while she was pregnant with Bud. Bud mentions that his mother was sick for six days in a row before she passed away. Bud tells Miss Thomas that he found his mother dead in her room and that she did not suffer at all. Throughout the novel, Bud thinks that Herman E. Calloway is his biological father, but it turns out that Herman is actually his grandfather.