It seems that your contention is that Sonny's environment is so difficult for him that he attempts to escape it through his use of heroine. For your points that will defend the threats that Sonny's environment contains, you may first wish to allude to the setting of Harlem in the 1950s as an area of darkness. For, as the narrator reflects that Sonny had probably tried heroine when he was the age of the students that the narrator teaches, he remarks,
They were filled with rage. All they really knew were two darknesses, the darkness of their lives, which was now closing in on them, and the darness of the movies, which had blinded them to that other darkness, and in which they now, vindictively, dreamed, at once more together than they were at any other time, and more alone.
- This darkness of the lives of those in Harlem is alluded to often. In a flashback the narrator recalls how his father drank to quiet his fear of the darkness. The mother, too, sat quietly as she and the father looked at "something a child can't see." And, as the narrator speaks with Sonny's old friend, the narrator senses the menace in the darkness of his environment. It is this menace that the parents of Sonny and the narrator have feared in "the vivid, killing streets" of their childhood. The darkness is the limits upon the lives of those in Harlem.
- These streets of Harlem as menace take something from the inhabitants. The narrator recalls how the mother said, "It ain't only the bad ones, nor yet the dumb ones that get sucked under." Then, she told the narrator about his uncle who was killed. The menace is the problem of race.
- Finally, there is the suffering that one endures in the Harlem of Sonny and his brother. Frequently, the narrator mentions "some worry" in Sonny's eyes, a "thoughtfulness" and the music "seemed to be merely an excuse for the life he led." It also "makes something real" Sonny tells his brother. But, later the narrator finds that the music seems "to soothe a poison out" of the street singers. As he and Sonny listen, Sonny remarks,
"While I was downstairs before, on my way here, listening to that woman sing, it struck me...how much suffering she must have had to go through--to sing like that...No, there's no way not to suffer. But you try all kinds of ways to keep from drowning in it, to keep on top of it, and to make it seem--well, like you."
Sonny feels the terrible darkness, the menace of the streets, and he plays his blues to "soothe a poison out," to get someone to listen to his expression of suffering and take away his "cup of trembling." Then, he triumphs, for he is not alone, not in the darkness. His suffering, his artistic expression is heard and shared. "And his triumph, when he triumphs, is ours," the narrator remarks.