Incessant, quick, confident knocks at the door kick off “Trouble in Mind” at the Yale Repertory Theater. The knock knock knocking reflects the stiletto clad assurance of Wiletta Mayer (Faye Butler); it also reflects the hilarious, fast-paced repartee of the play’s dialogues. What it doesn’t do is prepare the audience for a shaking anti-lynch mob finale: a single heavy blow to counter the light persistence of the knocking.

“Trouble in Mind,” written by Alice Childress and directed by Irene Lewis DRA ’66, is about a black actress who, after being cast in stereotypical mammy roles throughout her career, finally lands the lead in an anti-lynching play called “Chaos in Belleville.” As the rehearsals progress, Wiletta is forced to make the confrontation she has avoided all her life. Going against the rules of submissive acceptance that have enabled her to survive in the theater industry, Wiletta bravely challenges the white “Belleville” director and his play’s reinforcement of prejudices in a white-dominated society.

A powerful Wiletta, Butler skillfully manages the shifts from self-confidence to the insecurity of confrontation, and finally to confidence through that confrontation. She puts unexpressed emotions into a soulful voice when she has to sing for her role. Daren Kelly as Al Manners, the director of “Chaos in Belleville,” strikes a fine balance between annoying arrogance and occasional sympathy. It is easier to understand his desperate attempt to produce a play palatable for a prejudiced society than to condemn him for being prejudiced himself.

The play’s dialogue starts with Wiletta and her co-actors instructing an idealistic, young black actor on the key to survival: “Laugh. Laugh at everything they say. White folks can’t stand unhappy Negroes.” What they do not express, however, is that they have taught themselves to laugh, not just at the idiotic remarks of white people, but also at themselves, at the hardships of life, at whatever difficulty they can transform into light banter to make it more bearable.

For the entire first half, the audience laughs with them — the lines are witty, the actors playful. It somehow becomes amusing, and not disturbing, that Wiletta said nothing but “Lord have mercy,” in a shrill voice that she imitates so well, for the entirety of her last role. And when the callow, white Judy (Natalia Sears) expresses naively that it is horrible how black people are being treated, it is she — not the racist society — that comes off as preposterous.

There are brief moments of tension in the first half, like when the director asks Wiletta to pick up trash lying at Judy’s feet, but these conflicts — to the audience’s amusement — are subordinated to the first act’s strong comedic elements.

After intermission, the pace of the play slows down significantly under the burden of dramatic, almost melodramatic, monologues by the black actors who finally start expressing the disturbing realities of racism they have suppressed for so long. This unexpected change in tone is emotionally effective; it reminds you that the subject of racism is not supposed to be funny, and makes you reflect on why you’ve been laughing all along.

The themes of the play are painfully valid 52 years after its first performance off-Broadway in 1955, and the play relies on this: The production preserves the conventional feel of the 1955 show instead of adding innovations that will make it more relevant to contemporary audiences. Lewis chose not to address how the concept of racism may have changed over the decades.

While the play is relevant nonetheless, it is not groundbreaking. And ending with a quote from the Bible may not be satisfactory for cynical modern audiences.

That said, after seeing “Trouble in Mind,” it will be difficult to watch Mammy in “Gone with the Wind” again without feeling a little troubled.