Imagine an August Wilson play performed by the African American a cappella group Sweet Honey in the Rock, and you’re getting close to the feeling evoked by Nambi E. Kelley’s lyrical “For Her as a Piano,” now in a world premiere with Pegasus Theatre Chicago.

Kelley is of course no stranger to Wilson’s work — her performance as Risa in the Goodman’s production last spring of “Two Trains Running” was justifiably lauded. But where guarded Risa speaks volumes through what she doesn’t say, letting her glances and deliberate walk reveal her inner turmoil, the women in “For Her as a Piano” contain verbal universes of language and legacy, poetry and pain. Tracing three generations of African American women’s experiences — political activist Sarah (Toya Turner), her thwarted musician mother Mary (Nadirah Bost), and defiant-but-broken grandmother Delores (Toni Lynice Fountain), the pioneer to Chicago in the Great Migration — Kelley provides an elliptical and frequently compelling fugue about how we wrestle with our personal family legacies.

“Fugue” is actually appropriate at a couple of levels. In addition to the contrapuntal interweaving of voices in Jaret Landon’s original compositions, the three women also occasionally exist in a sort of fugue state. This is most true for Mary, whose struggles with mental illness provide the generational connective tissue. As Kelley’s story flows back and forth between present and past, reality and fantasy, some narrative details get a bit fuzzy. But she almost always manages to bring it back around to one act committed by Mary when Sarah was a small child that reflects both Mary’s own tormented childhood and her inability to fully transcend that pain.

The presence of a piano throughout the three women’s histories feels like a tip of the hat to Wilson’s “The Piano Lesson,” where siblings fight over a piano whose carvings contain the history of their slave ancestors. Sarah’s tour guide through her family’s history is simply called “Piano.” As played by Camille Robinson (decked out in