What are the motifs in Out of the Dust by Karen Hesse?

Clearly, music is central to Billie Jo and her story as well as a motif in the book. At first piano is a passion for her, and then it is a way out of this place. It is a comfort and an escape. After Ma dies, Billie Jo's journey inward is expressed outwardly in her musical struggles. Music is so much a part of her that when she can't play for herself, she goes to listen to Arley make his music.