The first major New York revival of “The Sign in Sidney Brustein’s Window,” Lorraine Hansberry’s 1964 Broadway play, comes to BAM this month. What took so long?Lorraine Hansberry’s “The Sign in Sidney Brustein’s Window” began performances on Broadway in the fall of 1964. It closed the following January, days before Hansberry’s death, having run 101 performances.It was hardly a flop. The reviews were generally admiring, and the support of the theater community, who rallied to keep the show going, was unstinting. Of the new plays that opened that fall, only a few ran so long. But unlike “A Raisin in the Sun,” Hansberry’s earlier Broadway show, which remains a staple of regional theaters and high school classrooms, “The Sign in Sidney Brustein’s Window” has been occluded, all but forgotten.“Isn’t that insane?” the director Anne Kauffman asked.This was on a recent afternoon in a rehearsal room of the Brooklyn Academy of Music, where Kauffman and her stars, the actors Rachel Brosnahan and Oscar Isaac, were preparing for the play’s first major New York revival since a 14-performance run in 1972. Combining the published script with earlier drafts, Kauffman’s production is scheduled to begin performances on Saturday. She directed a revival of “Sign” at Chicago’s Goodman Theater in 2016. But she didn’t feel finished with it.Rita Moreno and Gabriel Dell as the play’s divided married couple in the 1964 Broadway production of “The Sign in Sidney Brustein’s Window.”Billy Rose Theater Division, The New York Public Library“I loved that production. I really did,” she said. “But I had no idea what I was doing compared to the depths that we’re going to on this one.”A couple of days earlier, I’d watch a half-dozen actors, mostly off book, dip their toes in, negotiating a brisk scene that touched — sardonically, sincerely — on issues of race, gender and sexuality. The sign itself, a campaign poster for a local politician, had yet to be hung, which led to jokes: The Sign on Sidney Brustein’s Balcony, The Sign on Sidney Brustein’s Fire Escape. The actors navigated the scene’s particular rhythms and its many props: cigarettes, ashtrays, a fruit bowl, liquor bottles.“I don’t know where this will go,” Brosnahan, holding a glass, said.Kauffman responded: “That’s the fun of rehearsal.”“Sign” is set in Greenwich Village in 1964, territory more or less familiar to both Isaac (“Inside Llewyn Davis”) and Brosnahan (“The Marvelous Mrs. Maisel”). Dedicated to “the committed everywhere,” the script moves between naturalism and a more heightened, poetic style. At its center is the fraught marriage between Sidney (Isaac), a small-business owner and onetime idealist, and Iris (Brosnahan), a would-be actress. All around them are the tumults of the time, which are also the tumults of our time, as each character measures the gulf between who they were, who they are and who they would like to become. In exploring Sidney’s allegiances, some of them misplaced, and Iris’s bid for self-determination, the play opens up questions of competing loyalties, identities and habits of mind.James Baldwin, who was Hansberry’s friend, described himself, in a speech that he gave to raise funds for it, as deeply moved by the play. “If it cannot survive then we are in trouble,” he said, “because it is about nothing less than our responsibility to ourselves and each other.”Why was the life of “Sign” so brief? “Very simply put, it’s not a play about Black people,” said Joi Gresham, the director of the Lorraine Hansberry Literary Trust and an adviser on this production. “She was seen as going out of her lane.”“I want people to be exposed to these words at this moment and to know Lorraine Hansberry in a different way,” said Anne Kauffman, seated on the couch. She directed a 2016 revival of “Sign” in Chicago but felt there was more to explore.Erik Tanner for The New York TimesOnly one character in “Sign” identifies as Black, which surprised white critics who had buttonholed Hansberry as a writer devoted to Black characters. They had expected another “A Raisin in the Sun,” and not a protest play about Village bohemians.All these decades later, the play can be understood as a prescient work about apathy, action and mutual aid. David Binder, the outgoing artistic director of BAM and a longtime champion of Hansberry’s oeuvre, sees it as a work whose time has come. “It’s a play about folks trying to do well in the world, in an incredibly turbulent time,” he said during a recent interview. “They’re trying to do right, personally, politically, socially. There’s never been a better time than now to do this play.”Isaac agreed. “I want it to feel very alive,” he said. This was on that recent Saturday afternoon. Isaac, curled, beside Brosnahan, into a corner of a prop sofa, with Kauffman just opposite. They had stayed after rehearsal to discuss commitment, change and the ways in which a nearly 60-year-old play can still surprise us. These are edited excerpts from the conversation.Are you sign people? Are there signs that you hang in your own windows?OSCAR ISAAC My mom’s house is in Vero Beach. Trump country. During the election I put a bunch of Biden stickers on the golf carts.RACHEL BROSNAHAN My husband and I drove cross country in an RV in 2020. There was signage everywhere. Lawns filled with hundreds of Trump flags. I put a tiny Biden sticker in our window. It couldn’t be too big. We had to sleep there. If we did the play now it would be, “The Post on Sidney Brustein’s Instagram.” It’s all signs and not a lot of substance. You can hang a sign about anything. It’s maybe why I’ve always been a little bit allergic to signs.ISAAC Makes you feel like a hypocrite.BROSNAHAN But I go back and forth all the time. I sit on the board of a charitable organization, and I’ve learned how powerful it is to make a post on my Instagram. I guess the answer is you have to do both. You can say what you want, then you have to do it.What made you want to do this play?ISAAC It’s around the corner from where I live, a really easy sell. But I tried to get out of it. It’s nights. It’s a big commitment, energetically. I was like, ‘I’m going to read it just to make sure.’ I started reading the first pages. And I was like, ‘No, of course, I’m doing this.’ There’s something about the music of it. It’s undeniable. The draw is just too strong.Kauffman, center, with Isaac and Brosnahan. “It’s like this lost Bach piece,” Isaac said of the play, which begins preview performances in Brooklyn on Saturday. “People should hear this music.”Erik Tanner for The New York TimesBROSNAHAN I had a similar experience. And it couldn’t be further from my house. I’ve spent the last 10 months shooting and really needed a break. But there is a magnetism to this play. I couldn’t stop thinking about it and dreaming about it.ISAAC It’s like this lost Bach piece. People should hear this music.Who is Sidney, and what does he believe in?ISAAC I don’t know. I don’t know if he knows. He is a feeler and someone who’s trying to stop himself from feeling. He’s committed to a lot to things that haven’t panned out. So his hope has dried up. He has a very broad mind and a really keen aesthetic. He’s steeped in the culture of the moment and in the culture of the Village but it’s all starting to dissolve and change. There’s a wave coming — the civil rights movement, the psychedelic movement, Dylan plugging in. And at the heart is this relationship that’s also mutating and shifting. He can’t hold on to anything.Who is Iris?BROSNAHAN Iris is also a feeler. And a dreamer. But she doesn’t know how to achieve the dreams. She has a clear picture of what the dream is and no road map. She’s caught between two different waves of feminism. She’s caught between wanting to be cared for and wanting to take care of herself. When she entered into this relationship, she was really happy to be whatever he wanted her to be, to do whatever he wanted her to do, to go wherever he wanted. That was enough. But the world is changing, new conversations are happening. She is in a moment of tremendous change.The play is nearly 60 years old. What has surprised you about it?ISAAC The way she talks about identity, that feels eerily prophetic. What’s surprising to me is that this queer Black young woman, in the ’60s, wrote this play that has so much freedom. Every character has moments of extreme selfishness, ignorance and ugliness. Then, within a sentence, they say something that breaks your heart. You don’t see that kind of bravery these days.BROSNAHAN She gives each and every character the grace to be exactly who they are. She’s extraordinary. And so much of her extraordinary self is in this play. She could hold so many prophetic ideas in her head at once. We are revisiting a huge conversation right now about white apathy and the consequences of that in our political system and world. She explores that with such nuance in this play.Oscar, you mention identity. Sidney is Jewish as written and you were not raised Jewish. Does that make you feel any particular responsibility?ISAAC We could play that game: How Jewish are you? It is part of my family, part of my life. I feel the responsibility to not feel like a phony. That’s the responsibility, to feel like I can say these things, do these things and feel like I’m doing it honestly and truthfully.Has the play made you reflect about your own commitments, your own beliefs?BROSNAHAN I’ve been very inspired by the play’s criticism of inaction. As someone who can be an absolutist, very all or nothing, it feels like a very hopeful and healthy reminder that you can do something, even something small, even something local. If that’s all you can do, that is enough. If we all do a little bit, we have the ability to make great change. Lorraine believed deeply in people’s ability to make change.ANNE KAUFFMAN Doing this play and having people come watch it and making sure that it’s accessible, that’s my mission. People need to hear her voice and they need to see this play.BROSNAHAN We need her in this moment.KAUFFMAN In every moment. We haven’t even caught up to her. The way that she thinks.What do you want the audience to experience?ISAAC I want it to feel very alive. I want it to feel like a happening.BROSNAHAN I want it to come off of the page. Hopefully people will consider where they do or don’t see themselves in this play and how that moves them.KAUFFMAN I want people to be exposed to these words at this moment and to know Lorraine Hansberry in a different way. I want to have this be part of the canon. This is not a well-made play. You come expecting to see a Lorraine Hansberry play and this colors way outside the lines. My goal is to let it be wild, not try to tame it. More