Summertime, and the living is easy… Okay, that's probably a premature declaration. Our point is that Part 7 is set in the summer of 1935.
Billie Jo is doing her ambiguous poetry diary act again and it's kind of hard to tell what's going on here. Let's walk through it and see if we can figure it out.
Based on the title, we can infer that Billie Jo's having another dream, like she did after the accident—instead of a nightmare, though, she's dreaming of playing piano. She describes the peace and comfort of playing, and in the dream, music is the same refuge she once saw it as. No choppiness, no pain, no stops.
Although she looks and acts exactly like her father, Billie Jo also realizes that the piano is a mirror through which she can see her mother's reflection. Music is the legacy she left her.