At the heart of The Piano Lesson is a brother and sister couple at war over the question of using the family legacy. Berniece, the sister, fiercely protects the piano from being sold. She figures as the guardian of the family's past. Unlike other characters, the stage notes for Berniece are somewhat sparse, describing her as a thirty-five-year-old mother still mourning for her husband, Crawley. She blames her brother, Boy Willie, for her husband's death, remaining ever skeptical of his bravado and chiding him for his rebellious ways.
Berniece still constantly thinks about Crawley and has refused to re-marry. Though the play ultimately stages her seduction by Lymon—in some sense to recuperate her femininity—it is crucial that she figure as a woman-in-mourning. In this respect, she doubles as her mother, Mama Ola, a woman who, in her mourning for her husband, spent the rest of her days attending to the piano that cost him his life. Berniece will continually invoke her memory against her brother and his own appeals to his father, thus appearing as heir to a certain maternal legacy. Indeed, her mother led her to the piano in the first place.
Berniece played for her mother as a child, and served as priestess in the channeling of the family's ghosts, her music enabling her mother to speak with her dead father and animating its carved figures. The adult Berniece now leaves the piano untouched in an attempt to lay these spirits to rest. Moreover, she has refused to pass the piano's history onto her daughter and celebrate it within the family. Berniece can do nothing but carry the past and its traumas with her. In the final struggle between Willie and Sutter's ghost, Berniece will play the piano and resume her old role as priestess, calling the family's spirits to assist in the exorcism. Mystically, she will at once speak from the family's place of origin (Africa) and address the family's spirits from the present. Berniece thus assumes her duties as the link to the ancestors.
Berniece's brash, impulsive, and fast-talking brother, the thirty-year-old Boy Willie introduces the central conflict of the play. Coming from Mississippi, he plans to sell the family piano and buy the land his ancestors once worked as slaves. His impulse is to use the family's legacy practically—that is, convert it into capital. In this sense, Willie will appear guilty of a denial or turn away from his family's traumatic past.
Willie approaches everything with a certain boyish and occasionally crude bravado. He is especially vehement on questions of race. Declaring himself the equal of the white man, he continually refuses to accept the racial situation that he imagines the others accommodate themselves to. Thus he insists that he lives at the "top" rather than the "bottom" of life and remains intent on leaving his mark on the world. Aware of the fear he arouses in whites, he knows that he wields the "power of death"—that is, the power both to risk one's life and kill if necessary—that ostensibly equalizes all men. Though the white man may wield the legal and political authority to punish him, he will only follow laws that he considers just.
Willie seeks Sutter's land as a means of standing shoulder-to-shoulder with the white man. Moreover, in a play intimately concerned with memory and inheritance, he imagines this purchase in terms of a certain paternal legacy. By selling the piano, he avenges his equally brash and impetuous father, Boy Charles, who spent his life property-less, doing as he might have done. The mark he would leave on the world memorializes the father. Similarly, he proposes that the family should consider the day that Boy Charles stole the piano their own holiday and their own Day of Independence. In light of this legacy, it is also not for nothing that Willie's namesake is his grandfather, Willie Boy, the slave who transgresses white authority, the carving of the piano, and leaves a literal "mark" on the world that sets the story in motion. In the final scene, Boy Willie comes to incarnate these paternal ancestors, engaging in a battle with Sutter's ghost that allegorizes the struggle between white and black across the generations. Though Berniece's call to the ancestors will lead him to understand the importance of the piano, he in a sense he already lives in the memory of his ancestral legacy.
One of the most memorable characters of the play, Wining Boy is a wandering, washed-up recording star who drifts in and out of his brother Doaker's household whenever he finds himself broke. A comic figure, he functions as one of the play's primary storytellers, recounting anecdotes from his travels, glory days, and the family history. He is one of the two older players in Wilson's scenes of male camaraderie, playing a sort of godfather to Lymon when he deftly sells him "magic suit" with the promise that it will assist him in the arts of seduction. Finally, Wining Boy also appears as the other character in the play who can speak to the dead, conversing with the Ghosts of Yellow Dog and calling to his dead wife, Cleotha. As with Berniece, his musical abilities apparently put him in closer communication with the deceased, the call and response of the play's many songs oftentimes a call across the grave as well.
Doaker is Berniece and Boy Willie's uncle and the owner of the household in which the play takes place. He is a "tall, thin man of forty-seven years, with severe features, who has retired from the world." Doaker has spent his life working on the railroad, representing one of the play's more explicitly historical portraits of 1930s black experience. Within the plot, Doaker attempts to remain neutral with regards to the conflict over the piano, washing his hands of the piano in his guilt over his brother's death. He also functions as the play's testifier, recounting the piano's history. Like Wining Boy, the other member of the family's oldest living generation, he offers a connection to the family's past through his stories.