The piano which is the featured object in The Piano Lesson by August Wilson is full of family history and represents a lot of family suffering for both the original owners and for Berniece's family.
The Sutters were a white slave-owning family who owned the Charles family, black slaves who worked on the Sutter farm. Sutter did not have enough cash to purchase the piano as a gift for his wife, so he sold two members of the Charles family to pay for the instrument. One of those was Mama Berniece Charles, and her husband memorialized the two members of his family who had been sold by carving their likenesses (with permission) into the wood of the piano.
The Sutters kept the piano after his slaves were emancipated, but a member of the Charles family stole the piano in 1911, claiming that stealing it was symbolic of his family's freedom. This act, he believed, would free the Charleses forever. The piano has remained in the Charles family ever since, and Berniece took it with her when she moved, in 1933, to Pittsburgh.
Though he has never before expressed much interest in the piano, now her brother, Boy Willie Charles, has come to demand that Berniece sell the piano and claim his half in order to finance his business venture. Berniece is against the idea, and her arguments do seem to outweigh Boy Willie’s simple but burning desire for money.
Even though Berniece is an antagonistic character for most of the play, she does understand something about the piano that he either does not see or does not appreciate. She tells him:
Money can't buy what that piano cost. You can't sell your soul for money. It won't go with the buyer. It'll shrivel and shrink.
She understands that selling the piano is tantamount to selling something which is sacred to her family; in contrast, the only legacy Boy Willie sees in the piano is the money he will get from selling it. He claims to believe this sale is honoring his father’s legacy because Boy Willie is going to use the money to buy the land on which the Charleses were once enslaved, but it is a shallow honoring, at best.
Unlike her brother, Berniece clearly recognizes the significance of this piano to her family’s history, and she knows it is something tangible they will be losing if the sell it. She says:
Mama Ola polished this piano with her tears for seventeen years. For seventeen years she rubbed on till her hands bled. Then she rubbed the blood in…mixed it with the rest of the blood on it.
Bernice appreciates the sacrifice of blood represented by the piano.
Unlike Boy Willie, Berniece has a spiritual connection to this piano; despite that, she is unwilling to play the piano herself, believing that doing so would unleash the power of her ancestors. Eventually, though, Berniece releases her fears and reclaims her heritage by playing the piano and exorcising Sutter’s ghost which has come to reclaim the piano and torment the family. Berniece plays and sings:
I want you to help me/I want you to help me/Mama Berniece/I want you to help me/Mama Esther/I want you to help me/Papa Boy Charles/I want you to help me/Mama Ola/I want you to help me.
She calls on not only her own ancestors but all of her race of people to help her, and they do.
It is clear that Berniece’s connection to the piano is stronger and more spiritual than her brother’s, and that is why she deserves it more than Boy Willie.