The Broadway opening of Seven Guitars March 28 adds a seventh chapter to author August Wilson's epic of African-American life in the 20th century.

Starting with Jitney in 1982, the North Carolina-born playwright has been constructing a cycle of plays, one set in each of the decades of the 20th century. Seven Guitars, which is set in1948 Pittsburgh, is the seventh play in the cycle. Only the first decade of the century, and the last two, the 1980s and 1990s, now remain to be written.

Two of the plays in the cycle, Fences for the 1950s and The Piano Lesson for the 1930s, won the Pulitzer Prize for Drama.

Many of the plays are set in Pittsburgh. Nearly all debuted at the Eugene O'Neill Theatre Center in Connecticut and went on to productions at Yale Repertory Theatre in New Haven. All have been directed by former Yale Rep artistic director Lloyd Richards.

Here is the state of the dectych (or dectette, considering Wilson's oft-acknowledged debt of inspiration to blues musicians) so far: 1900s -- Not yet written.

1910s -- Joe Turner's Come and Gone is the story of Southern blacks passing through a Pittsburgh rooming house on their way to new lives in the North -- and one visitor who is on a mystical quest to find a mysterious "Shining Man."

1920s -- Ma Rainey's Black Bottom is the story of a group of blues musicians who gather at a Chicago recording studio to cut a record, but wind up in a murderous argument about God, and whether He has it in for blacks.

1930s -- The Piano Lesson: A family must decide what to do with a hand-carved piano that was traded for the freedom of the family's patriarch back in slave days. Should they hold onto their heritage -- or sell it to start a new life? And what about the increasing evidence that the piano is haunted?

1940s -- Seven Guitars: A group of Pittsburgh musicians are preparing to set off for Chicago to achieve fame and fortune. But somehow their dreams threaten to destroy them.

1950s -- Fences: A former star athlete, now a Pittsburgh garbage man, struggles to stop his own ruined dreams from destroying his teenage son's.

960s -- Two Trains Running: The regulars at a Pittsburgh lunch counter try to figure out a way to get the economic, social and spiritual goods they believe have been denied them, and which they feel should be coming to them. While they struggle, the local madman takes steps to get a ham he believes he is owed, while the local undertaker patiently awaits them all.

970s -- Jitney: The first play in the cycle Wilson wrote is a portrait of life among Pittsburgh's independent cab drivers. It's the only play in the cycle never done on Broadway, thought it's being revived by the Pittsburgh Rep (appropriately) this spring.

980s -- Wilson said this yet-untitled play is currently being written.

990s -- Perhaps forming in Wilson's mind as you read this.