What role does music play in Selina’s life, and in the story?

What role does music play in Selina’s life, and in the story? Revisit the passages where Selina sings in response to her neighbors’ threats (2367) and when she hears the woman singing in jail (2370-71). Compare the role of music in this story to its role “Sonny’s Blues.” Does music play a similar or different role in these two stories and in the lives of their characters?