Sonny days

In the story “Sonny’s Blues,” by James Baldwin, the narrator of the story discovers from a newspaper that his younger brother, Sonny, has been arrested for selling and using heroin. His students, he realizes, could someday end up like Sonny, given the obstacles and tough times they face growing up in Harlem. At the end of the day the narrator heads home, but he notices that one of Sonny’s old friends, who is always high and dirty, is waiting for him by the school. The two men walk together, talking about Sonny. Time passes, but the narrator never writes to Sonny in prison until the narrator’s young daughter, Grace, dies. Sonny writes a long letter back to his brother in which he tries to explain how he ended up where he is. The two brothers then stay in communication. When Sonny gets out of jail, the narrator, his brother, is there for him. He takes Sonny back to his own family’s apartment. The the narrator takes us back to an extended flashback, Sonny told his brother about his dream of becoming a jazz pianist, which the narrator dismissed. Although Sonny loved the music, the rest of family had a hard time bearing his constant practicing. After having Sonny live with him for a few weeks, the narrator debates whether he should search Sonny’s room. As he paces back and forth, he sees a street-corner revival occurring outside. Eventually Sonny comes home and invites his brother to watch him perform later that evening. The two brothers go to a small jazz club where everyone knows and respects Sonny. He watches all his brother’s struggles come pouring out as he plays, and only then does he finally realize who Sonny is and what he’s made of.  

In this story I noticed that back then a lot of musicians got into heavy drugs, and Heroine was a popular one at the time. So I wonder if Sonny being a musician caused him to get into the drugs or was it the life he lived growing up in Harlem?