There are many pleasures to be had in watching Patti LuPone perform, particularly on a Broadway stage. There’s her powerful, flexible singing voice, undiminished at age 70. There’s her operatically expressive face, her sharply detailed characterizations. There’s also the plain fact that to see LuPone at maximum, commanding intensity — her default mode — is to see that most thrilling and increasingly rare of theatrical sights: a true diva. (And one who has endured a diva’s share of backstage drama.) “I knew at 4 years old where I was going and what I was going to do,” said LuPone, a two-time Tony Award winner who will be starring in a revival of Stephen Sondheim’s “Company” next year. She added with a snap, “And I didn’t think I was going to be in the chorus.”

There’s a bit of a paradox going on with Broadway musicals right now. On one hand, they seem to be in good shape, because shows like “Dear Evan Hansen” and “Frozen” are making so much money. But on the other hand, those shows are not really vehicles for traditional musical-theater stars like yourself. “War Paint”1 was that kind of show and struggled to find an audience. Does that at all make you wonder where you fit in the Broadway ecosystem these days? No. But some of those shows should be in Las Vegas and not on a Broadway stage. The thing really bugging me now about Broadway musicals is that they’re making me deaf. They’re all so damn loud. But you don’t know what’s going to hit. You don’t know what’s going to flop. I was disappointed that “War Paint” didn’t catch on, because it was beautiful, and Christine Ebersole and I played like gangbusters. How can you know why it didn’t hit? It could have been where the theater was located. It could have been because other musicals attracted people. So when you ask me how do I fit: I know that I have box-office draw, and I know that I’m relied on for it. In a way, that’s unfair. The pressure shouldn’t be on me to draw a crowd. The pressure should be on the producers.

There was a time on Broadway when having a theatrical star like Mary Martin or Ethel Merman in a show was a guarantee that it would play for at least a full season. Is that kind of star power a thing of the past? No. They used to write for the stars, and they don’t anymore. Cole Porter and Richard Rodgers were writing for Ethel. So you know you had a good combination. But I don’t think it’s over. Last night, there was a line for the cast of “Betrayal,” especially for Charlie Cox and Tom Hiddleston. Hugh Jackman is going to come onstage for “The Music Man.”

But Hugh Jackman and Tom Hiddleston are movie stars who can draw an audience to their stage work. Ethel Merman and Mary Martin were Broadway stars. There’s a difference. O.K., you’re right. Unless you have some sort of broader visibility, it may be harder to pull an audience. I think I’m a product of that old line of musical-theater women, because I don’t have that other thing to bring people in. Some people may know me from “Life Goes On”2 or “Steven Universe,”3 but most know me mostly from musicals. Actually, they know me most from the commercial for “Evita.”4

Patti LuPone in the Broadway production of ‘‘Evita’’ in 1979. Photograph by Martha Swope, from Billy Rose Theater Division, the New York Public Library for the Performing Arts

Which was a good commercial. Can I ask you a random “Evita” question? Why does Evita sing “Don’t Cry for Me, Argentina” when she does? Isn’t everyone happy for her at that point in the show? I don’t get the narrative logic. I thought the same thing. I was going, “What the hell is this song about?” I understand exactly what you’re saying. I never wanted to do “Evita,” because it was the most bizarre music I’d ever heard. You’re raised on Rodgers and Hammerstein, Meredith Willson, Lerner and Loewe, and then you hear that? I heard the “Evita” concept album, and I went, “Ow, my ear.”

Did you read Andrew Lloyd Webber’s memoir?5 No. Am I in it?

Oh, yeah. Oh, dear.

He rehashed the expected stuff.6 He also made a point of criticizing your diction. John Houseman7 used to call me “flannel mouth.” You don’t know, when you’re in the moment, that you’re not enunciating. As an audience member, I can understand the problem. I saw “The Iceman Cometh.” I did not understand a word those guys were saying. I’ve seen a lot of theater where I don’t understand what the actors are saying, because they’re forgetting that they need to project. They need to enunciate. In some of my performances, I was oblivious to that; I was busy emoting. Apparently, when I was doing “Three Sisters,” John Houseman wanted to yell at me about my diction. They kept him away from me, until he literally strangled me.

John Houseman and Patti LuPone (both front and center) with members of “The Acting Company” in 1975. Jack Mitchell/Getty Images

Literally? Literally put his hands around my throat and said, “I want to beat you black and blue until you’re bloody all over and you have bandages all over your face.” And I’m going, Well, that’s bizarre. Then I just went to pieces. But I’m an emotional, organic actor, and that gets in the way of me technically speaking clearly. So the fact that criticism of my diction follows me around makes total sense. Was Andrew Lloyd Webber talking about “Sunset Boulevard”?

He was talking about “Evita.” How could he talk about “Evita”? The whole thing is sung. He’s a jerk. He’s a sad sack. He is the definition of sad sack.

Do you like any of his music? I thought “Evita” was the best thing he and Tim Rice did. But the rest of it is schmaltz.

We talked about how what’s popular on Broadway has changed. But I’m wondering, too, if you’ve seen any differences between your generation of performers and younger generations? Yes. I am blown away by the talent onstage in New York, but I see too many actors relying on microphones. They do not know how to fill a house with their voice, and therefore their presence. That’s bad. And so is when somebody doesn’t know the history of theater, or who Marlon Brando or Shirley MacLaine or Chita Rivera are. It’s like: What are you doing this for? Are you doing it because it’s a time-honored profession? A necessary profession for society? Or are you doing it because you want to be famous and rich?

You’re seeing more of that than you used to? I think basically everybody wants to be famous and rich, but I don’t see the commitment, maybe. It takes sacrifice. It’s hard work to delve into a character. It’s hard work doing eight shows a week. It’s hard work to protect your instrument, which is your entire body. I say: “Eight shows a week. No life.” That’s exactly what it is if you’re onstage.

Lupone in her dressing room backstage before a performance at Lincoln Center in 1987. Catherine McGann/Getty Images

A couple of years ago, you were saying you thought you had done your last Broadway musical. But you’re going to be back on Broadway, playing Joanne in “Company.” Did you feel as if you had to reckon with what Elaine Stritch8 did in that part? I imagine that, even just because of the D.A. Pennebaker documentary that we’ve all seen, it would be hard not to have her somewhere in your mind. It would have been hard not to have Ethel Merman in my mind for “Gypsy.” It would have been hard not to have Zoe Caldwell in my mind for “Master Class.” It would have been hard not to have Angela Lansbury in my mind for “Sweeney Todd.” These are great actors. Well, Ethel was not such a great actor, but these are icons. Elaine is Elaine, and I am me. Steve Sondheim actually said to me, years before I did “Company,” that he was surprised that I understood “Ladies Who Lunch.”

What was that supposed to mean? Exactly! I think he thought that I was of the lower classes and wouldn’t understand the Upper East Side. I was surprised that he would think that I wouldn’t be able to do it. Then I was thrilled that he thought I could. You go through all these things in your mind. You’re going, Really? Then you’re going, Oh, great, he loves me! It’s crazy.

Do you still have doubts about Sondheim’s estimation of you? Always.

Do you still care? Of course. He’s the master. Some actors don’t care. I do. I wanted validation. I think Stephen thinks I’m a strong person and — I don’t know. I’m speculating on what he thinks. I don’t know what he thinks. Maybe he took a dislike to me early on in my career. Maybe I’m making this whole thing up. Maybe he likes me. I don’t know. But I know that he’s happy with this production of “Company” and was happy with my performance. I think.

You know, in Arthur Laurents’s9 memoir, he wrote about taking you out to lunch before your doing “Gypsy” and going over some performance ruts that he thought you’d fallen into. What was he talking about? “Ruts”?

He used “ruts.” He never told me that. Here’s the deal. I was raw meat having gone through that lovely experience of “Sunset Boulevard.” I come home, and I get a telephone call. I’m offered a play by Arthur Laurents: “Jolson Sings Again.” I read the play, and I didn’t like the play. It wasn’t very good. I said, “Are you bringing this to Broadway?” And I was told, “No, we’re doing it in Seattle.” I went: “I just spent a year in London. I’m not going to pack a suitcase and go to Seattle.” So I said no. Then the producer David Stone got it, and they were going to do it on Broadway. But the deal was completely unacceptable, so I turned it down. Oh! I’m missing a whole part. First, I got a call from my manager at the time saying Arthur Laurents wants you to go to his house and meet with him. I went. I knocked on the door. Arthur answered, and then out from behind him came David Saint, who would direct the play. I saw a weak chin on that one. I was like, He’s not going to direct me. Then Arthur was very convincing, and I went, Yeah, sounds great.

LuPone and Manoel Felciano in a scene from the revival of “Sweeney Todd” in 2005. Paul Kolnik

Then what happened? The deal was terrible, and I passed! Then I’m shooting “Heist” in Montreal, and I’m in my hotel room, and I pick up the phone, and it’s Arthur. He told me I sank his play. In my head I thought, No, actors don’t sink plays; playwrights sink plays. I did say to him that the deal was terrible. Then he hung up on me. The next thing I heard was that I was banned from his work.10 All of it. I thought: Why me? I just turned down a play. Why am I getting beat up? Why do these things happen to me?

What’s your answer to that question? I’m telling you the truth: I don’t understand it. I don’t understand if it’s because people think I can take it because I’m tough as nails. If I am, I’ve been made tough by this business in order to survive, in order to continue to perform, which is what I was born to do. They’re not going to stop me from getting on a stage. Whatever they tried to do, they, whoever they are, didn’t succeed. But it did succeed because I felt it.

Felt what? I’ve been bullied in this business. There’s something that happened that I did not put in my book,11 and I wish I had. Hal Prince12 did something to me. My persona in this business has not been: “Let’s bed Patti. Get on the casting couch, Patti.” It’s either been: “Nope, out the door,” or getting slammed on the head. The bullying with Hal Prince had been in the book, and out of respect for the guy, I took it out. I wish I had left it in, because when we talk about bullying, it has to be better defined. I’ve been bullied all my life.

By whom? Starting when I was a kid. My dad13 was the principal of my elementary school. I remember going to kindergarten, and I got hit in the face with a snowball with a rock in it. I always carried around that it happened because my dad was the principal. And my dad bullied me in front of my class. It wasn’t bullying — he didn’t know what to do — but in today’s world, you would call it bullying. I ran out of line at school and embraced my father, and my father didn’t even look me in the eye; he took me by the shoulders and put me back in line without explanation. I was humiliated, not understanding what happened. Do you treat a kid that way? Now, take all that bullying that you get used to as a child — because apparently that’s what life is — and then you’re in show business, and it’s the same thing. In the case with Hal Prince, what happened was so scarring that I said, “I will never work with this man again.” And I never did.

Can you tell me what happened with Hal Prince? Well, it was a rehearsal with the New York company of “Evita” after he had just opened the L.A. company of the show. He started the rehearsal with a bullhorn turned up to 10, saying, “The L.A. company is better than you are, and now rehearse!” Then maybe 10 minutes into it, he accused me of changing blocking. I went, “No, you changed it in previews.” An argument — this humiliation — ensued for the entire rehearsal. I ended up in a fetal position in my dressing room, crying my eyes out. Stage management came in, and I said: “Why didn’t you defend me? The changes were in the prompt book.” They were Hal Prince’s men, the stage management, and one of them said, “Oh, honey, he does that to all his leading ladies.” As if it were acceptable. That was a form of bullying, but you just go, O.K. I never understood it.

Is bullying still accepted in the theatrical world? Maybe not now. I don’t know how I feel about bullying in show business, because it has made me stronger. Sometimes you think: Is this a test from the gods? Is it what you have to go through to get what you want? Or is it just abuse? In a lot of cases, it is just abuse. But what do you do? There was nobody I could talk to. That was my ignorance. I should have called Equity. I should’ve walked out of rehearsal and called my agent. But I would’ve been fired, and I knew that. What Hal Prince did has never left me. It did many things besides humiliate me. It diminished my status in the company as the leading lady. He treated me like a stupid chorus girl. It was so demoralizing and defeating. He actually said, “Now, who’s going to win this argument?” I said, “You, because you’re the director.” He said: “That’s right. Now sing.” “Evita” was the thing that shot me to stardom, but when I say I didn’t like the experience, that’s one of the reasons. It was hard as hell.

LuPone as Helena Rubinstein and Christine Ebersole as Elizabeth Arden in the musical ‘‘War Paint’’ in March. Sara Krulwich/The New York Times

You described yourself earlier as an organic, emotional actor. That force-of-nature aspect of what you do is a huge part of what people like about your performances. Is that also what you like about what you do? I am a tragedian. I am a comedian. I am fearless on a stage. I’m scared to death in my own life. Paranoid. Terrified. But put me on the stage, and there’s nothing I won’t do to the fullest. It hasn’t been easy. But there was nothing that was going to stop me from doing what I was supposed to do. This was my calling. Does that answer your question?

Sort of, but let me go a little deeper. You must know that when people buy a ticket for a musical with Patti LuPone in it, they want to see Patti LuPone be Patti LuPone up there onstage. They don’t want a shrinking violet. Do those expectations affect how you approach a performance? I don’t know what people are coming to see. How much I commit depends on what is required from the script. If you want to go the distance — and I always want to go the distance — I will let it out. The fact that there’s a deep well inside me is just how I was built. That’s the Italian in me. There were a lot of big emotions and big fights and big sobs growing up. When it was required of me to express those things in a role, I found that the well went deeper and deeper and deeper. That has to do with what I’m made of.

You said you’re scared in your life. Of what? Everything. A boogeyman. I am terrified when I go home to Connecticut at dusk. I close all the first-floor blinds, because I’m afraid somebody is going to be looking in. If I hear a noise, I’m awake and scared. I don’t know where that came from. But the fearlessness onstage is because that’s home to me. There, I’m not afraid.

This interview has been edited and condensed from two conversations.