The flashback scene in which the narrator's mother reveals the story of his uncle's death occurs at a pivotal point in the story. The narrator's father has just died, and the narrator is forced to confront his feelings of responsibility for his brother, Sonny. The new knowledge that his uncle was killed by the reckless behavior of white men explains many aspects of his father's behavior that he had not previously understood, such as his intense anger at the world and his strong negative attitudes towards whites.

Like Sonny, the narrator's uncle was a musician, and the depiction of his death includes a graphic description of the destruction of his guitar. Though this connection is left implicit in the story, it is clear that in the narrator's mind music, as well as a certain careless, free-spirited attitude towards life, is an attribute shared by both his uncle and his brother. The story drives home the importance of protecting his brother from a hostile and indifferent world.

In a flashback, the narrator recalls a conversation with his mother in which she was using experience from his father's past to provide some advice in dealing with Sonny.

Just like Sonny, their father's younger brother was "maybe a little full of the devil, but he didn't mean nobody no harm." The two young brothers enjoyed Saturday night entertainment spent playing guitar and singing together, and they had not many cares in the world when they were young. However, on one Saturday night, a car of white men intentionally hit the narrator's father's younger brother--and these men never stopped.

This tragedy forever changed their father, and he was never the same man. The narrator's mother cautions him in two ways using this experience. First, she notes that brothers look out for each other. Together they may or may not ever face a car full of racist white men, but Sonny and the narrator will certainly experience the trials that life will bring, and she wants to make sure that they will stick through it all together. She warns, "I'm telling you this because you got a brother. And the world ain't changed." Second, she realizes that Sonny has a personality that could lead him into the troubles of life, much like her young brother-in-law walked into trouble that night. She tells the narrator,

Don't let [Sonny] fall, no matter what it looks like is happening to him and no matter how evil you gets with him. You going to be evil with him many a time. But don't you forget what I told you, you hear?

This is advice that will begin to haunt the narrator in his estranged relationship with his brother years later and will provide a guiding force for reconciliation.

In one segment of a memory flashback in "Sonny's Blues," Sonny's brother recalls a conversation with their mother during which she tells a family secret about their uncle, their father's brother. The narrator is seven years older than Sonny and though they were close in the darkness of suffering caused by racism and the darkness of escape from suffering through movies, he feels the separation caused by the seven years; at one point he worries about whether those years can ever be bridged. Their mother reveals a tragedy that affect their father and his brother.

The narrator learns that their father's brother, their uncle, was shot down by drunken white men. Their father lost his brother to the wild brutality of racism. Their mother is make an earnest plea by way of an object lesson that the older brother, the narrator, promise to always take care of Sonny because brothers are important and, at times, all the help that each has.

This family secret, kept from the boys in an attempt to reduce their suffering, sets up the  narrator's conflict because he doesn't know how to help Sonny and has given up on him. It also points out that suffering comes, as is said above, from wild racist brutality, the life darkening brutality of racism. Since this is so, the brothers need to appreciate each other and stand by each other and the elder must promise to help the younger to prevent them both from being drowned or shot down by racism.