What events prompt the narrator to write his brother? (Sonnys blues) how would this story be different if sonny told it
The narrator is unconvinced early in his life that he owes any allegiance to his brother. The narrator holds fast to the opinion that those who have been unsuccessful in life, including his brother. This opinion and bias is clear in the early scenes between the narrator and Sonny's old friend, when the narrator barely conceals his disgust for the uneducated drug addict. The narrator has been caught up by social standards. He has worked to achieve that status of a teacher, pillar of the community, head of household of a nuclear family. That is the way to success. He does not understand that others might seek the same level of control he is seeking in another form. This is evident in his dismay that Sonny has turned away from classical music in favor of jazz. Jazz, being on the social fringe, is beneath classical. However, for Sonny, jazz is a type of control. Jazz allows Sonny to control the music.
What finally leads the narrator to write to Sonny is the death of his own daughter. Losing a blood relation has caused the narrator to wonder about his family, about his own dead father, and about Sonny, and he chooses to seek him.