Twenty-seven years after it first premiered on Broadway, composer Stephen Sondheim and librettist James Lapine’s subversive, fairy-tale-based musical “Into the Woods” comes to the screen Dec. 25 under the direction of “Chicago’s” Rob Marshall and with a cast including Meryl Streep as the Witch, James Corden as the Baker, Emily Blunt as the Baker’s Wife and Johnny Depp as the Wolf..

On a recent blustery night in New York, Marshall, Streep and Sondheim gathered for an intimate conversation with The Times about the play’s twisty path to becoming a film, the modern scarcity of movie musicals and the virtues of “actors who can kind of sing.”

Over French fries and a bottle of wine, Sondheim compared himself to Eminem, Streep marveled at the emergence of the blue-hair trend and Marshall was scandalized by the concept of technologically enhanced singing.

You talk like you’ve known each other a while. How long have you all known each other?

Rob Marshall: Steve, I met you when I was doing Broadway shows as a dancer. … The real first time was when I worked with Hal Prince on “Kiss of the Spider Woman.” And I came in to choreograph that.

Meryl Streep: Well, I’ve known him much longer.

Marshall: You did [Aristophanes’] “The Frogs.”

Streep: In 1973. I’m the only one who can remember the chorus.

Marshall: And then, I did two shows with Steve as a choreographer. One was a revival of “Company” at the Roundabout. And then I did a revival of “A Funny Thing Happened on the Way to the Forum.”

Stephen, when you did “Into the Woods” on Broadway, did you think of a film adaptation coming down the line?

Sondheim: No. You never think of those things when you’re writing a show. I mean, maybe some people do. There’s no way of knowing whether it would attract an audience — particularly in an era when musical movies are not as frequent as they used to be, like the ’30s and ’40s. So no, never. Never occurred to us. What did occur was that, if the show worked, it would have a great future life in schools, colleges and regional theaters.

Marshall: It’s the third-most-performed production in schools. I know everybody is touched by that in some way. I hear it from everybody. The people that came to audition for the film all said either they were in it in school, had seen it in school, their sister was in it in school, somebody — some connection to the piece. It’s really amazing.

Streep: Well, I think that’s what happened with the movie industry. They caught up with the appetite that was bred in the high schools. They always are slower than the people.

Sondheim: Well, there have been many attempts to do this movie. [Another] Marshall was going to do it.

Marshall: Penny Marshall.

Sondheim: And there was a read at her house. Do you know about that cast? It’s pretty remarkable. Robin Williams as the Baker, Cher as the Witch, Steve Martin as both the Wolf and — wait a minute. No — and Danny DeVito as the Giant. That, I remember. Roseanne Barr as Jack’s Mother. Baker’s Wife, Goldie Hawn.They read through the script. The script was an adaptation by the guys who wrote “Parenthood,” Babaloo Mandel and his partner, Lowell Ganz. There was also — during this period, Jim Henson was going to be part of it. And the puppets were going to play the animals.

Meryl, you had seen it on Broadway with Bernadette Peters in the role of the Witch. What impression did the show make on you at that time?

Streep: I loved it. It was unlike anything else that I’d ever seen. And it was so unexpected. How it turned was sort of shocking.

Sondheim: Did you take your kids?

Streep: I was a child myself 20 years ago. It was ’87. So I had a couple kids. But they were little bitty. I never imagined in my wildest dreams that, when I’m 65, I would be playing the part of the Witch. Never. I mean, it just was out of the realm of imagination.

Sondheim: I’m sorry. It was ordained. Here’s a scoop for you. It’s ordained because the lady who played the Witch on the stage and the lady who’s playing the Witch in the movie, their last names are anagrams of each other.

Marshall: Only Steve would know that. He’s a genius at puzzles.

How do you like playing a heightened character like the Witch?

Streep: Gosh, I guess it is heightened. Is it heightened? … The first scene, when I climb up to Rapunzel and I give her blackberries and then I come down and I see that she’s seeing this dreadful man … all I’m doing is trying to keep her safe. That was something that … didn’t feel heightened or weird.

Sondheim: That’s interesting about fairy-tale characters because fairy-tale characters are heightened, aren’t they? They’re … “archetypes” I guess is the word.

Streep: Yeah. But you can’t play an archetype. You have to play something specific. And when you say heightened, it makes me think of the freedom of sort of more abstract movement and things that Rob allowed us to push ourselves physically in ways that normal movies would never allow you to do. In the Witch’s transformation, he was determined that that not be …

Marshall: There’s no CGI in that at all.

How did you do that?

Marshall: Well, first of all, you — Meryl is incredibly physical. I mean, she’s a dancer. I can’t tell you how many times she fell doing the work because she throws herself into it. Literally on the ground a million times. It was a combination of things. … There’s very little CG in the film because we couldn’t afford it, number one. But it’s also not my taste. I want the actors to be able to touch and feel where they are, not just be in a green room and working in a space where they can’t have any kind of connection to the world. Little Red Riding Hood’s tree, Granny’s tree is real.

Streep: The first time we encountered the set, I thought, the trees are a little too big. It’s like, OK, too much. And then, we went into the forest. And the forest — when Jack climbs that tree and says, “There are giants in the sky,” you know that moment? That’s an actual tree — in Windsor Park [England], maybe 500 or 600 years old.

Why did you want to use real trees as opposed to build a set?

Marshall: Because you can’t ever build with all the imperfections and the beauty of that. You can never really capture that. We did have a stage, H stage, which is one of the biggest sound stages in Europe, where we created our woods.

Streep: In the forest set, you piped the music in every day. Usually, you make a movie, it’s in silence. You’re talking, blah, blah, blah. And then, they put the score in six months later. You go to the screening, and you suddenly — it feels like a movie. But this felt like that world already. It really did every day.

How is it different to sing Stephen’s songs versus other composers’ songs?

Sondheim: Gee, me and Eminem, we’re exactly …

Marshall: Steve can shut his ears. But I think he’s the greatest living composer and lyricist there is. And it’s a gift for an actor to sing a Sondheim song in any way because Steve is an actor. He understands how to create for the actor all of it.

Streep: There’s so much room for interpretation. As indelible as Bernadette [Peters] was, in the part there was a way to find my own voice in this like there is in great plays.

Sondheim: What’s remarkable about Meryl is how many different ways she can sing a given lyric. … Each take was like looking at the facets of a stone from a slightly different angle each time. Remember, what’s difficult about acting in a song is that you are strait-jacketed by certain rhythms and certain inflections. They come from the rise and fall of the melodic line, from the periodicity of the tune. So you’re not as free as an actor as you would be if you just give the speech. You have to do it in a certain rhythm. I said to Rob, “So how are you going to pick which one? You’ve got the tray of desserts.”

Marshall: There are musicals, if you take the song out of the scene, it can live or breathe without the song. If you take a song out of a musical that Steve’s written, there’s no scene because something happens in the song.

I heard, Stephen, that originally Rob came to you and said that he wanted to do one of your musicals. And you thought this one was a good fit for him. Why was that?

Marshall: This was a long time ago. Steve had me over to his beautiful townhouse. It was right after “Chicago.” I’m sure I initiated it and said, “I’d love to speak to you, Steve,” and he said, “Please, come on over.” We talked about “Sweeney Todd.”

Sondheim: But Sweeney had been, as we say, spoken for.

Marshall: He said, “I think ‘Into the Woods’ would be great for you.” I remember him saying that to me very clearly. And I wasn’t sure why.

Sondheim: Looking back on it now, I’d say it’s because it’s the most musical — and I’m trying not to use the word “musical comedy” — but [I’ll] have to use it. It’s the most musical comedy, meaning the one that has a certain traditional feeling to it and yet requires an imagination. And if you look at “Chicago,” that’s — in its own way, as a traditional musical, except it’s not traditional at all. But it’s a traditional musical. Number, scene, number, scene, number scene. It’s not an attempt to, you know, do an opera or anything. It’s just traditional in that sense.

Marshall: You know what somebody said to me last night that I love so much? She said, “I had no idea when they were singing and when they were speaking.”

Sondheim: That’s the highest compliment you could get for something like this. … That was your mother, was it?

How did you think about your audience in terms of both the age and also their familiarity with the musical?

Marshall: Listen, my great hope is that families see this piece because I feel like it’s about parents and children. You were just talking about that beautiful sequence, Meryl’s song. She loves this child so much and so thinks that she’s giving her the perfect parenthood and giving her the great love. And because of how she was treated, she was cursed with ugliness. So her response to that is to protect her child at all costs and give her all that love. And kids that I’ve seen haven’t moved watching it. They’re not rustling around because I think it asks a lot from them. It asks them to participate and make decisions. When Steve writes, “Giants can be good, witches can be right,” there’s a sense that kids have to figure it out for themselves. I love that participation.

Sondheim: Which is what fairy tales are about — moral decisions. When we were trying the show out in California originally … James [Lapine] and I sat down and discussed, “What is the show about?” Well, it’s actually about two things. One, it’s about the relationship between parents and children. And the other is about community responsibility. In the second act, they have to get together to kill the threat. And it’s hard to — we decided finally it’s about both, which is dangerous when you do a show, you know. You look at fairy tales, you know, most of them, the fathers are either dead or missing in most traditional fairy tales. It’s because it was passed down. Mamas would tell them to their kids. And it is about the difficulties of raising children when the fathers are either off to war or hunter-gathering.

Streep: The rest of the sagas all are about boys — vanquishing dragons — and fairy tales are about girls. Be careful. Be careful. Don’t talk to strangers.

Marshall: What’s so interesting about the Cinderella tale in this one is … she chooses to run home each night to an abusive home. … Steve and James took that and then created this character who couldn’t make a decision about where she wanted to be.

Sondheim: James did what nobody’s done in 500 years, which is he said, “I think she left the slipper behind on purpose.” Nobody has ever thought of that in 500 years. And nobody — none of the reviews, none of the commentaries have mentioned that.

That’s one place where this movie and the show depart a little bit, when Cinderella sings “On the Steps of the Palace.”

Marshall: That on stage is a presentational number, which means you sing directly to the audience. So who is she singing it to? I asked James and Steve — I said, how would you feel if this happened in the moment? … Steve, would you adjust the lyrics so that it all takes place in the present time. … You can freeze the moment. And then, there’s an internal monologue. That was the joy of it, to reimagine something but still keep the core of what it is, which is this indecisive character making the decision ultimately not to decide. … You know, you have to reimagine something for film. And that’s — and James and Steve, from the very beginning of the work on this piece were unbelievably flexible, which says so much about them. They understand how musicals work.

Was that hard for you, Stephen?

Sondheim: Not at all. Come on. It’s a movie. We had many, many arguments and I’d say, “I don’t think that’s a good idea” — but the whole point is to make a movie. Who is going to sit there and say, “I’m terribly sorry. I want her coming down stage to the camera?” Nobody is going to say that.

Marshall: I’ll give you a couple names. He doesn’t know. He’s very rare. He’s very rare. I’ll speak for Steve here. He loves film. He would scare you with his knowledge of film.

Sondheim: I was brought up on movies.

Streep: So what other one of your musicals do you think would make a good movie? And are there any old ladies in it?

Sondheim: Well, actually, first of all, [librettist and playwright] George Furth had the best idea for “Company,” and nobody picked up on it. What George Furth wanted to do with a company was make a movie which can star all real-life married couples. Natalie Wood and Bob Wagner — five actual married couples and Warren Beatty. [laughter] Now, come on, don’t tell me that isn’t a brilliant idea for “Company” 40 years ago?

Emily Blunt told me something that made her feel at ease on this movie, Stephen, was that you said you preferred actors who could kind of sing to singers who could kind of act.

Sondheim: Well, that’s what I like. But there are people who disagree. I prefer the dramatic — I prefer the storytelling aspect. I think that’s the strongest thing in any given stage piece. So I’d rather have an actor who can sing. On the other hand, you know, you get something that requires some vocal chops like “Sweeney Todd,” and yeah, when I hear it sung I think, I see what I was missing. But most of the time, I would rather have actors who could sing.

Marshall: Someone asked me today in an interview — and I wanted to literally kill them — they said, “So when Meryl opens up in those huge — you know, with that huge, amazing voice that Meryl has, did you enhance that in some way?” I said, “What are you talking about?”

Sondheim: That’s a natural question. Come on, Rob. People haven’t heard her sing. People don’t know she has that kind of voice. So why wouldn’t they ask?

I do think it’s the expectation today, that when you see someone on “Saturday Night Live” for instance, there’s a track underneath sort of giving them a boost.

Sondheim: Just for Madonna.

Marshall: First of all, I don’t even know how to do that. … I’ll never forget when we were working on “Stay With Me” and I saw Meryl go there. And I saw her open up like that.

Streep: That was an exciting day, the very first day when everybody brought the story that they needed to tell. And everybody was really nervous because we’re, none of us, known as singers. We’re actors. We’re known as that first.

Sondheim: But also the excitement of singing with an orchestra — you know, we all sing in the shower. And then, you hear 40 pieces behind you …

Streep: It brings up your game.

I read that there was a new song written for Meryl that ultimately didn’t make it into the film.

Sondheim: It was called “Oklahoma.” [laughter]

Marshall: And we just didn’t think it was going to work.

Sondheim: No. What happened? There was a small fragment of a song in this part of the second act of the show. And Rob and a few others said, “You know, how about expanding and making a new song?” I said, “My worry is that it’ll hold up the story.” So I wrote a song, which I like very much, which she sang very well. And they put it in the film. And guess what? It held up the story. Another lesson I learned from Oscar Hammerstein is, if it holds up the story, out.

Marshall: I’m excited to say that it’s going to be on the DVD because it’s a beautiful song.

Streep: That’s why God invented the DVD extra.

Were you disappointed that it was taken out?

Streep: No. You have a sense of what’s right and there’s no question that that’s the right decision. This thing has a flow.

Sondheim: If they hadn’t allowed this to be on the CD, I would be really upset. You know, the strength of this, like the strength of “Sweeney Todd” and “West Side Story,” is the story. I’m not being modest about the scores or anything like that. But the strength is the story. And what happens next? There are certain shows like “Company,” “Follies” where that is not the case.

I was delighted to see that the Baker’s Wife still gets her big scene with Prince Charming. There were reports at one point that you were taking that out. Did you ever seriously consider that?

Marshall: Never. Not for a second.

Because there was a New Yorker story over the summer that quoted Stephen implying that scene would be cut, along with some others.

Sondheim: That was a true misunderstanding. That’s not what I was talking about. I was actually talking about Rapunzel’s death. I had a discussion with some teachers who have a lot of trouble with their school boards and putting on shows. And they wanted to talk about censorship. They naturally asked, was there any difficulties with Disney? What I didn’t want to talk about — because I didn’t want to give away the plot — was we did have a big argument about whether Rapunzel should die or not.

Well, lots of theater geeks will be relieved to see what you didn’t change.

Marshall: One of the reasons I asked James Lapine to write the screenplay and asked Steve to work with us on it was I wanted to make sure we maintained the core, the central elements of this piece and honor this beautiful, beloved piece. I love the piece on stage. But I also know it would do a disservice to the piece on stage not to reimagine it as a film. It’s the most important part of it. Otherwise, you’re — you know, it doesn’t work if you just put it up on film.

Sondheim: He says that casually. It’s very hard to reimagine a stage piece as a film. They are such different mediums. And it’s really hard. It isn’t just about opening up, “Hey, we’ll have a shot of the entire forest.” That’s not what it’s about. It’s about rhythm. It’s about intimacy with the actors.

As a reporter who covers movies in 2014, it’s hard for me to imagine that there used to be as many movie musicals as there are comic book movies now. Why do you think there aren’t more? They often do well.

Marshall: They’re fragile to make work. You’re always on that border of — Steve and I have talked at length about this — why are they singing? So when it doesn’t work, it’s an uncomfortable moment when they start to sing because it hasn’t been earned, or the language hasn’t been set up at the beginning. When musicals don’t work, they really don’t work. But when they work and someone is singing because they can’t speak anymore, or they’re dancing because they can’t move anymore, moving is not enough to express — it’s this beautiful thing.

Streep: Why are there not more musicals? Because they undervalue half of their audience.

You mean women show up for them?

Streep: Absolutely. Absolutely. Over and over and over, it happens. That audience will come, and they will drag their husbands.

Sondheim: There’s another thing too. People no longer listen to songs in a dramatic context. Forty years ago, you know, you hear a song like “Some Enchanted Evening,” whatever it was, it was part of some big dramatic fabric. That’s not true anymore.

Streep: But there’s a new language, which started with MTV and with music videos …

Sondheim: But do these songs tell — are they part of telling a story?

Streep: Some of them are.

Sondheim: Well, OK, if you say so.

Streep: I’m staking my life on this. I have money down on this because I really, really believe younger audiences are way, way, way ahead of the executives that think they can only make things about robots. I think it’s in them, and it’s in them since high school. You know, they — there’s a huge, huge, huge audience.

Meryl, your hair in this movie is so great.

Streep: Don’t you think it’s going to catch on? Blue hair.

Blue hair is a thing with twentysometing hipsters in L.A. right now.

Sondheim: Come on.

I’m not kidding. I thought you guys had your fingers on the pulse.

Streep: Cool. So we’re right on trend.