How did Herman Calloway interrrupt his plans?

Herman Calloway interrupted his plans by unexpectedly taking in Bud Caldwell, the protagonist of "Bud, Not Buddy." Initially focused on his music career and maintaining a stable life, Calloway’s encounter with Bud forces him to confront his past and the relationships he has neglected. This disruption leads to significant changes in his personal life and ultimately contributes to Bud's journey of self-discovery.