The Manhattan Theater Club’s production of “The Country House,” written by Donald Margulies, directed by Daniel Sullivan and starring Blythe Danner, debuted to a star-studded audience at Manhattan’s Samuel J. Friedman Theater on Thursday night, including Danner’s daughter Gwyneth Paltrow, newlyweds Neil Patrick Harris and David Burtka, Jennifer Westfeldt and Zachary Quinto.

Danner stars as a retired actress of stage and screen. In the wake of her daughter Kathy’s untimely death, she convenes her son Elliot (Eric Lange), her granddaughter Susie (Sarah Steele), Kathy’s widower Walter (David Rasche) and his fiancee Nell (Kate Jennings Grant) to the family getaway in the Berkshires for some soul-searching. Also joining is Michael Astor (Daniel Sunjata), a family friend who’s become a regular sitcom hunk — but still isn’t satisfied.

“I wanted to write something closer to home,” said Margulies at the Hard Rock Cafe-hosted afterparty. “I didn’t want to have to immerse myself in the imagery, the borrowed history, the weightiness required for my last play, ‘Time Stands Still,’ which was about photojournalists. So I decided to write about theater people.”

“I’ve worked in the theater for many, many decades. I’d never written about it before. I don’t pretend this is a searing indictment of commercialism, or anything like that – but the arguments that are there, inherent in these characters, they have a lot of opportunity for conflict. There’s this need to be realistic about how does one earn a living?”

“The Country House” had its original run at the Geffen Playhouse in Los Angeles back in June. Four of the six original cast members returned for the Broadway production, with Grant and Rasche joining.

“There were a lot of changes, a lot of deepening and a lot of rewrites,” Danner explained. “It really grew. They (Sullivan and Margulies) were really there with us for the whole thing, and it was definitely advantageous. This is the best role I’ve ever seen, really, as an actor in many years.”

Danner vouched for the play’s accuracy in depicting the struggles of a family of performers. “I think it’s a lot of truth, and so many people in the business in the audience, you can hear it in their reactions.” (When Danner’s character said, “There are no Broadway stars, dear. Not anymore. Oh, there are stars on Broadway, but they’re not Broadway stars,” the theater erupted in whistles and applause.)

“It’s so hard, but it’s so true: people who feel entitled, or people who feel jealous, it covers all three dimensions of the theater actor’s experience.”

Of his role as the rakish TV star Michael, Sunjata mused on the cautionary nature of Margulies’ plot. “He’s done his Hollywood insanity thing, dating models and doing drugs, he’s by no means a perfect guy, but he is seeking a meaning to life. He has all the accoutrements of success, and still his life is ringing hollow. Now, that story has been told before, but we’re trying to do it with some level of originality.”

But the most buzzed-about performance might have been Lange’s, whose turn as Elliot, Anna’s tortured, self-hating and very wry son, takes the play in a surprisingly heavy direction in its second act.

“I think, in L.A., Elliot was a little more of a raw nerve. The highs were higher, the lows were lower, and here we’ve dialed it in a little more, to make it a little more swallowable for everyone… Mainstream him a little bit, so he’s not such a fringe character.”

“He’s the guy at the party who everyone’s like, ‘just shut up, please.’ And then when you find out why he wears those masks, it’s heartbreaking. His sense of humor, his dry wit, it’s all just a protective mechanism so nobody sees that he’s still just a little boy. He just wants to be loved.”

Lange is normally a mainstay of TV and movies; “The Country House” was his first play in 8 years. “I read it and I cried. I don’t care what I lose. Nobody tell me what I’m gonna miss out on. I wanna do this play, I’m out.” It’s his Broadway debut.

(Pictured: Gwyneth Paltrow and Blythe Danner backstage at “The Country House” opening night)