Laurie Anderson’s performance at Sanders Theatre last year was chilling and soothing. Just four days after airliners full of innocents were smashed into the Pentagon and the World Trade Center, she turned her Cambridge tour stop for the album Life on a String (Nonesuch) — already a dark, sensitive work inspired partly by the death of her father — into a prayerful reflection on loss and the unsteady possibilities of the future. As if the ripe ideas that have always tumbled from her best stories and songs weren’t proof enough, her on-the-spot improvisations that night — buoyed by the airy melodic character of her voice — were the work of an artist of the highest caliber.

Anderson’s gift for touching the hearts and minds of her audience has not faltered since the single "O Superman" thrust her from the downtown New York City performance-art scene into the mainstream in 1981. It’s withstood the scrutiny that’s come with making major-label pop albums like Mr. Heartbreak (Warner Bros.) and major multi-media works for the stage, like her four-hour epic United States and Moby Dick, which had an early run at Cambridge’s American Repertory Theatre.

This Saturday, she once again returns to Cambridge to try out a new work. Happiness is a one-woman show — a stripped-down affair that allows her to control its pulses and beats like a DJ while she plays violin or keyboards and spins a non-linear 95-minute narrative that she calls her most personal work. The music propels stories of her hospital stay at age 12, after she broke her back in a swimming accident; her recent experiences working at a McDonald’s and on an Amish farm; and even the events of last year’s Black Tuesday. At least, they do now. Although it debuted in Los Angeles in January, Happiness remains a work in progress. And its 55-year-old creator is still fine-tuning the text, trying to define her search for the meaning of "happiness" and "justice," among other things.

Last week she spoke by phone from her New York studio about Happiness and the philosophical bones it chews, as well as her performances with her mate Lou Reed in Italy this summer.

Q: Your last performance in Boston was right after the September 11 attacks.

A: I remember it very well.

Q: It seemed you were altering texts and improvising to reflect that week’s events in an attuned, sensitive way.

A: Yes, that’s true. But a lot of things seemed to take on another resonance then, no? You’d look at paintings and feel, "Whoa! That has to do with now!" I find it really interesting how much of our perception we bring to something. The songs I did were what I planned to, but it was the things that were happening in between that I was doing on the spot. That was really live. It was awake. It was a wonderful time to do music.

Q: Did that spontaneity in part inspire your approach to Happiness? In your artist’s statement, you mention that the work leaves room for plenty of improvisation.

A: Well, I thought there was going to be. I’m revising it quite a lot. I don’t know what will happen in Boston, so I better figure that out pretty soon.

Certainly in comparison with something like Moby Dick, which had very strict musical arrangements and technical cues, it’s a lot more improvised, but not as much as I thought it would be. Through performing I’ve found something that makes a lot of sense as the core, then I change around it.

Q: Another thing in your artist’s statement was intriguing. You wrote that Happiness explores your interest in "the evolution of behavior" and "the meaning of justice." That makes me think about definitions of what’s acceptable and unacceptable behavior, and it reminds me how loaded words like "justice" and even "happiness" seem today.

A: Oh, why do I write these artist’s statements? It’s like holding a gun to my head! Well, I’ve never really known what’s acceptable, or not, that well. To me, acceptable is often a kind of pallid politeness that doesn’t involve how you really feel. It involves just saying the social-glue stuff and leaving the rest out. Plus, I don’t want to judge. If someone tells me I’m doing something unacceptable, I think, "You don’t even know me. Why are you saying that?" What are the rules you’re applying here — to whom, when?

Q: I think of violence in that context. Certainly aggressive behavior has become more tolerated in our culture.

A: I agree with that. I’m not someone who judges that, because I like the energy of that a lot and I’m really afraid to live in a place where people tell you what to do and how to say things and how to act. So I’m glad there’s a lot of conflict. I do wish there was more on the other end. If there’s something I’d really love to see, it’s more — um — tenderness.

Q: What about "justice" and "happiness?"

A: Happiness is so loaded. It is such a cliché, but it has so much desire in it and so much junk. But justice, ah . . . I’m not even really sure how to address that now, because I was hoping I would do a better job in the piece, and maybe I’ll be able to write the link that I was looking for. I find it very difficult to think about that at the moment because it involves this judgment of good and evil. I find it very distressing that politicians have become moralists.

Q: "Justice" has been stretched to mean "vengeance" . . .

A: Yes. I’d hoped there was going to be more dialogue in the last year. That didn’t seem to happen. It kind of froze at "Why do they hate us? They hate us because we’re rich and democratic and free." That kind of thinking drives me crazy. It’s like the beautiful girl in high school saying, "People don’t like me because I’m beautiful." You know, people don’t like you because you’re a jerk and you treat everybody horribly. Where are the minds that are going to challenge that kind of good-and-evil bit? Ah! [exasperated sigh].

Q: Is it the case that your childhood diving accident and the September 11 attacks bookend Happiness?

A: They do, but I’m not sure what to do about that. That’s one of the topical things that I don’t really want to talk about in the piece now, so I’m tinkering with that at the moment. It may be resolved by being gone.

Q: Don’t you think you’ve been changed by the events of the past year?

A: I am overall looking at things differently. It does make me want to make things that are simpler. That’s part of Happiness as well. I just didn’t want to do another show. It wasn’t time to drag out all the multi-media stuff. I wanted to do something really simple and intimate.

Q: You’ve said Happiness is the first time you’ve used so much of yourself in a piece, yet it seems that all of your work reflects your interior mechanisms. It has intimacy.

A: I think intimate and personal are different. The way I used to be intimate in earlier pieces was to use the word "you" and figure out what I meant by that. I meant "you" the audience, "you" in general, or "you" sort of meaning . . . me. And as a way to talk, that was very intimate. But it’s the difference between having a conversation and having somebody tell you their life story. Not that this is my life story. But parts of it are, and not because I think my life is interesting. Well, I do think it’s interesting, but I think everybody’s life is interesting. It’s a way to talk about how we design our personalities. Using my own experience for part of the story makes it seem less abstract.

Q: How does Happiness sit in your gut now?

A: When I’m doing it, I really feel like I’m talking to people in the most direct way possible. I was afraid it was going to turn into a shtick. It hasn’t. It’s just the opposite. In the middle, I find myself thinking, "Why am I telling all these strangers this?" I don’t have tricks like actors must have, like how to get in and out of material without being so drawn into it. But I’m one of those people who can laugh at my own jokes and cry at my own sad stories. That’s been fun for me, and I didn’t really expect that to be the case.

In other shows, there have been times when I’ve known them so well and done them so often that I’d practically catch myself making a grocery list during them. My mind is going very far away, and that’s a really awful feeling. I start thinking, "What are you doing here? Don’t you care about this at all?" It was just so easy.

I did some shows with Lou Reed this summer in Italy, which was so much fun. It was a relief — for half the show I didn’t have to be the leader. He would do some things and I would. But in Happiness I really have to pay attention.

Q: Did you and Lou perform as a duo?

A: Yes. We were asked to play the literary biennial in Venice. They found this beautiful amphitheater for us. And we thought, well, let’s bring a guitar and a violin, and on it went from there. It was really a wonderful experience for me. We also did some of each other’s things, too. So that was odd — to hear my own words coming out of someone else’s mouth.

It was great fun and we were really nervous. It’s hard to find a good partner, if not impossible. It’s also hard to find a good collaborator, but not as hard as finding a good life partner, so we thought that if we disagreed about anything, we were going to quit immediately. But we had so much great fun, it was like walking into each other’s minds.

Laurie Anderson performs Happiness at Sanders Theatre in Harvard Square this Saturday, September 28 at 8 p.m. Call (617) 876-4275 or (617) 496-2222.