Playwright August Wilson’s “The Piano Lesson” comes down to this: A sister and brother, haunted by the violent disruption of their Mississippi childhoods, reunite in 1936 Pittsburgh. It’s a tense reunion, with the family heirloom’s destiny at stake. The piano of the title either stays put in the parlor, where sister Berniece’s daughter practices her scales though her mother never touches the keys herself, or it gets sold to help pay for brother Boy Willie’s farmland back home.

Faces of the family’s ancestors, carved by their grandfather, grace the piano with a metaphysical weight beyond anything measured by a hardware store scale. Wilson’s 1990 drama, the second of his Pulitzer Prize winners (“Fences” came first), is now a movie. It too is a family matter.

Malcolm Washington makes his feature directorial debut with “The Piano Lesson.” His brother John David Washington (“Black KkKlansman,” “Tenet”) takes the male lead as Boy Willie. They are two of the four children born to Pauletta and Denzel Washington.

The latter — in addition to everything for which you know him as a screen star — is a determined and powerful August Wilson champion, who has expressed more than idle interest in backing film versions of just about everything the poet-turned-playwright ever wrote. To that end: Denzel Washington directed and starred in the 2016 film version of “Fences” with Viola Davis, the two having headlined the play’s 2010 Broadway revival. “Th.