both berniece and boy willie are concerned with leaving differnt types of legacies for their families

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.

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.

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.

http://www.sparknotes.com/drama/piano/themes.html