How does this notion of limited possibilities and lack of hope help us to understand Sonny's choices in the story?

Sonny is poor and black in America. Sonny also suffers from drug addiction and depression. His options are fairly limited to low paying jobs and a life of crime. Sonny sinks into the Harlem underworld which offers bad habits and situations for Sonny to get into. Harlem, does, offer Sonny's salvation as well: Harlem gives Sonny Jazz. Jazz gives Sonny his identity formed from his African American heritage. Sonny is able to find and express himself through Jazz music.