Themes are the fundamental and often universal ideas explored in a literary work.

Memory and Historical Legacy

As noted by Wilson, the two questions that pervade The Piano Lesson are: "What do you do with your legacy, and how do you best put it to use?" The Charles' legacy is incarnated by the piano, an artifact and record of the family's history under slavery. Consequently, implicit in the question of legacy are those of vengeance, debt, and reparation across the generations. The two characters primarily confronting these questions are Berniece and Boy Willie. Whereas Boy Willie would sell the piano in the name of his future, a future that would avenge his ancestors and secure his success, Berniece clings to the heirloom in memory of the blood that stains its wood. At the same time, she leaves the piano untouched, never playing it and keeping its history from her daughter in fear of literally waking it anguished spirits. In contrast, her brother would proclaim its history with pride, enjoining her to pass it onto the future generations.

The siblings' reconciliation comes in the play's final scene, a struggle between Boy Willie and Sutter's ghost that allegorizes their families' and races' battle across time. Playing the piano anew, Berniece will serve as a priestess who links the household to its ancestors, calling upon them to assist the family in its struggle against the specter of the master. Thus Boy Willie comes to understand the importance of the piano—an importance beyond material concerns—and Berniece finds herself able to use her legacy.