The Piano Lesson's big finish happens when Berniece banishes the ghost of Sutter. Avery, a preacher, tries to exorcise the ghost by calling on the Christian God, but ultimately fails. It takes Berniece and her trusty piano to save the day. Here's how August Wilson describes the climactic moment in his stage directions:
It is in this moment, from somewhere old, that Berniece realizes what she must do. She crosses to the piano. She begins to play. The song is found piece by piece. It is an old urge to so song that is both a commandment and a plea. With each repetition it gains in strength. It is intended as an exorcism and a dressing for battle. A rustle of wind blowing across two continents. (2.5.202)
We find it very interesting that Berniece succeeds where Avery, a Christian preacher, fails. It's important to note, though, that when Africans were first brought to America as slaves they weren't Christian at all. They had a diverse background of beliefs that were completely separate from the European Christian tradition of their white slave masters. Over time, many of these tribal rituals and beliefs were lost as the slaves were indoctrinated into European American culture.
As we talk about in "What's up with the Title?" and in "Symbols, Imagery, Allegory," when Berniece plays on the piano she summons spirits of not only her direct ancestors, but also the spirit of the entire African-American community. When the stage directions say that the song is "A rustle of wind blowing across two continents," we're pretty sure those continents are North America and Africa (2.5.202). The "rustle of wind" could be the spiritual connection that Berniece has found with Africa. Berniece reaches deep down into her self and finds the essential African-ness buried in her. She finds the song that has been covered by centuries of white oppression.
This isn't the only August Wilson play which has this kind of ending. Check out our discussion of "What's Up with the Ending?" for his other Pulitzer Prize winning play, Fences, and you'll see what we're talking about. Really, check it out – you could write a great paper comparing the two endings.