Something happened to Carly Simon the moment she stepped onstage at the Chilmark concert. The performance she worried so about was riveting; the crowds she expected to be rowdy welcomed her warmly.

Backstage, she had mingled among the carefully screened (and tagged) collection of people, accepting hugs of encouragement, words of support.

“There was so much paranoia before the event, about what might happen, what it might turn into that I was really quite scared,” she recalled some days later.

This was also the largest audience Carly had ever played. (“During all of our tours, I limited my audience to 3,000, and I usually played clubs which generally sat about 400, because that’s the way I felt most comfortable.”)

It was a hometown crowd, an enormous gathering of 6,000 or more. The familiarity was at once comforting and terrifying; it came on like a giant rush.

There were prophets of doom aplenty on the Island. Not everyone shared the jubilation of Miss Simon’s fans nor of those who came embracing the anti-nuclear cause, or the spectacular fall day.

But she came on with a blast.

Whatever apprehension immobilized her for hours before the concert fled. She just got better and better.

“That seems to be my pattern,” she acknowledged during an interview with the Gazette.

“I make people feel — and myself feel — that I can’t possibly make it through. Then I get onstage, and somehow I pull it all together. Often, I’m nervous onstage too, but I wasn’t on Saturday.

“Something was more powerful than anything I was feeling, and that was the day and the whole idea of the day — the way it turned out, the scene there, the people, the cause. It was just one of those days that was transcendent in some way.

“It was a gathering, the likes of which I’ve never been part of before. Here were all those people from Martha’s Vineyard in one place, and a lot of the faces in the audience I knew. I was crying when I went onstage.”

Carly Simon is still high on the concert five days later.

This evening, she is sitting in a high-backed leather chair off the kitchen of the Vineyard Haven home she shares with James Taylor, her husband. Sarah and Benjamin, their two small children are just off to bed.

The dirt road leading to the Taylors’ home is long, bumpy and unmarked. The only signs are the usual Island postings — No Trespassing, Keep Out, Private.

The Vineyard population sports a vast selection of the distinguished, the celebrated. Most of them can maneuver inconspicuously down Main street or prowl through Alley’s undisturbed.

They are authors, Pulitzer Prize winners, statesmen, playwrights and columnists. Their faces are relatively unknown, even while their accomplishments are broadly acclaimed.

Life is different for Carly Simon and James Taylor.

Carly and James. Everyone assumes the first name because they are stars with a capital S, recording artists with gold records, concert givers who can sell out the Garden, celebrities instantly identified by their magazine cover pictures. To many, their marriage is a pairing of the beautiful and the charmed.

There was an instant at the Chilmark concert when Carly was watching Alex Taylor jump and sing onstage from the side. She was spotted holding Sarah, rocking her to the blues belted by A.T.

Nearby, the blonde, smiling teenager was ecstatic: “There she is. That’s her. I know it’s her. Quick,” she said to her boyfriend, almost dropping the Instamatic in her plunge. Then she leaped from her front field seat, a black T-shirt read “Carly” in glittering silver letters.

Pictures. A program autograph. Miss Simon obliged, then retreated backstage, remaining there until she was called.

“I’ve gotten used to it,” Carly said when asked about the fevered young fan.

“I’ve been there too, as a younger girl just adoring someone so much and having that person make my day. Even now, I’m starstruck by certain people that I admire terribly.

“When it happens, I just think, ‘My God, isn’t this incredible.’ It makes me feel humble and proud and sometimes uncomfortable. When somebody comes up to me and says, ‘I can’t tell you how much you mean to me. I’ve been listening to your music for years,’ then, occasionally, I just want to cry. I’m always very, very touched.”

The Vineyard has been home for Carly and James since they were infants, vacationing here each season. The Island holds some of their dearest friends, many of their happiest summer memories.

“I consider this more my home than anywhere else,” Miss Simon said tucking her bare feet beneath a flowing lavender dress. “I was born in New York, and I’m certainly comfortable there, but the Vineyard is solidly a part of my heart and soul than any other place I know.”

The Taylors divide their lives between an apartment on the upper west side of Manhattan and a rambling Vineyard home in the woods surrounded bu the fields they cleared. The house has a modern approach — glass hall walkways separating levels and rooms — with a Cottage City exterior flavor: wooden shingles and trim in a shade of chartreuse.

“Both James and I have to be in a city where we can work, and the children, or at least Sarah, can go to school. For the time being and in this day and age, it seems to be either Los Angeles or New York. They have the greatest opportunities as far as musicians and studios are concerned.

“We chose New York over L.A. because we like it better and because we’re East Coast people and it’s easier to get to Martha’s Vineyard from New York that it is from California.”

Carly hasn’t timed her family’s departure to the city. It’s October, and she says the fall is a productive season for her songwriting. The Vineyard summers are too full of family, friends and homelife for work.

“I find my life here is just as busy as it is in New York. I have many more friends here, Island friends, and there’s just more socializing in the summer. It takes up a lot of our time, and between that and the children and the organizing of the house and cooking three meals a day, I have no time for work.”

Miss Simon is a keen listener as well as a warm conversationalist. Her eyes move with the talk and absorb a visitor’s question or comment.

The shift from city to country and back again varies with recording schedules, responsibilities and travel. In either direction, Carly says she is a reluctant mover.

“I love this house. The last two years, we’ve spent four months here, and the two years before that we spent eight months here. Sometimes, I’m into my life in New York, and the move here seems like an unfortunate jolt at the time. Now, if I have to move back to New York, I’d feel the same terrible reluctance. I’m a victim of inertia to a certain degree in that I get comfortable where I am and I don’t want to move.

“It takes me a while to adjust to a place but once I’m there, I’m usually very happy. I’ve been lucky; I’ve never lived in a place that I haven’t liked.”

While she is here and when she returns, Carly may work to revive a piece of the past. The Mooncusser in Oak Bluffs was the first stage for many of the folk artists whose music was born in part or in whole on the Vineyard.

They were all there in the sixties: Jesse Colin Young, Jeff Muldaur and Maria Muldaur with the Jug Band, the Green Briar Boys, Tom Rush, James Taylor and Carly and Lucy Simon. Few of the Island’s young people missed a gig at the Mooncusser.

“It really started a whole lot of people on their careers,” she said and then beamed with the anticipation of a new Mooncusser. It would have to be in the right spot and, she added, it would need a liquor license “so we wouldn’t totally lose our shirts.”

“Listening to people there inspired other people. James started there and it’s where he heard me sing when he was 15 and I was 18. Tom Rush was really the staunch Island regular. He was the idol of all of us. It was very exciting. We were there every night, and we certainly saw every act that ever played there.”

Carly and Lucy were singing together then. At the end of her freshman year at Sarah Lawrence (she left after the second year), they went to Provincetown. It was a prep for the Mooncusser and the Mooncusser was it.

“It was the first summer we were performing. We came back from Provincetown where we learned three songs at our gig. By the Mooncusser, we had six or seven songs.”

Performing was unnerving then as it is now. Curling back into her chair, she said as frustrating as the technical difficulties were that Chilmark afternoon, it relieved her tension onstage. The distraction was welcome.

“It was like my opening night as a solo act in California,” she said, smiling her full smile at the memory. “I sat down at the piano and I played That’s the Way I Always Heart It Should Be, which was my hit at the time.

“The microphone at the piano kept slipping off to the left, and as I was playing there was nothing I could do but follow it. At the end of every bar, I would go like this,” she said, sweeping her hand across the air. “But it totally took my fear away, because I was constantly thinking about the mike and there were technical problems I was more involved in than myself.”

Of late, Carly has been receiving and rejecting offers which would broaden her musical career. Movies to star in, scores to compose. Does the national press have it right when they claim that Carly is looking for something more?

“It’s hypothetical,” she said shifting her position. “It’s always been a matter of priorities, and my family has always, always come first. If it happens that I make some music I’m pleased with and I’m situated in New York when the right movie comes up that’s going to be filmed in New York, I would definitely do it. But I’m not going to go out of my way to make a movie the way I would make a record or to find Sarah the right school.

“It’s a matter of timing,” she added.

Jackie Clasen, Carly’s masseuse, has just arrived. Would she mind waiting, Carly asks, until the interview is through and one-and-a-half-year-old Benjamin is moved off his mother’s bed and into his own room. Get yourself something to drink, to eat.

“It would have to be a movie I identified with or felt close to in some way,” she said returning to the question. “I’ve just been asked to write a score for a movie produced by Robert Altman. I haven’t read it yet but it sounds interesting.

“But there are lots of areas I could get involved in. I think while the children are small, it’s very hard to think about branching out and writing a Broadway score or acting. As long as I’m home the children are around and they come to me. I want to be there for them so something would have to fit in in a miraculous way.”

Walking the reporter to their large oak front door, Carly pauses by a stack of snapshots on the table. They are her Polaroid pictures. There’s Benjamin and Sarah (“Sarah was blinking.”) James in white tails, a necklace of flowers falling across his ruffled shirt. (“That was in Hawaii. Doesn’t he look terrific?”) Sarah and Benjamin. (“Sarah’s blinking again. She always blinks when I take her picture. Benjamin. He’s beautiful.”)

The Taylors will soon ready their household for a winter in New York. There’s music on the keyboard for recording, the studio is waiting. But Christmas isn’t far off now. They’ll be back to their Vineyard house in the woods for the holidays.