Why does Sonny's brother come back into his life?

Sonny's Blues is a story about pain, suffering, alienation, and anger; however, it is also a story about redemption. At the beginning of the work, the narrator is lost, disconnected from his family and isolated from his community. A painful act of grace--the death of his aptly-named daughter, Grace--allows him to begin to understand the depth of his brother's suffering. In that moment of pain, he contacts his brother, starting the long path to redemption. The brothers begin communicating and eventually Sonny is released from prison and stays with the narrator. When he finally listens to his brother play, the narrator understands and accepts the meaning of his brother's life. In accepting his brother, the narrator accepts himself and his heritage. The climax is a moment of discovery and redemption, in which the narrator is pulled back to his heritage and community, back to his brother and back to himself. He who was lost is now found.