When I met with choreographer Twyla Tharp recently in her sunny, spacious Upper West Side apartment with its stunning views of Central Park, I wanted to speak with her about “Come Fly Away,” her all-dance show accompanied by Frank Sinatra’s vocals that comes to the Kennedy Center April 18-29.

But foremost on Tharp’s mind was her new Web site, which she expects to unveil in a few months and which will document her process of making and remaking so many of her dances. So threaded throughout our two-hour conversation was the theme of origins — how her new works spring from past experiments.

“Any of the pieces that are really strong never came out of the box straightaway,” Tharp said. “This current Sinatra is the third pass at this; that’s not untoward. ‘Baker’s Dozen’ came out of some improv and the outtakes of ‘Hair.’ ‘In the Upper Room’ came out of a lot of improv I did, two motion pictures and three workshops, and a very long piece that was never shown. It’s not like these just pop out.

Choreographer Twyla Tharp, poses for a portrait in her New York City apartment on March 31, 2012. (Joseph VIctor Stefanchik)

“In the case of Sinatra, the first version that went up in Atlanta — another lifetime ago — was much longer and in many ways closer to the Broadway show, though the opening was changed for Broadway. ...It was a terrible idea. Not my idea.”

“Come Fly Away” has its origins in Tharp’s past concert dances inspired by Sinatra’s voice, primarily “Nine Sinatra Songs” from 1982. Some of the choreography in the new show is similar to that work, for example, the combative duet to the song “That’s Life.” But in “Come Fly Away,” the battle of wills is harsher, close to true physical battery. In “Nine Sinatra Songs,” Tharp said, “there’s, shall we say, more courtliness about it. There’s a line that’s generally not crossed, whereby it remains closer to the world of an apache, which is what it is, a stylized dance of violence. But very stylized.”

“The material is the same,” she said. “How they’re coached is different. ‘Come Fly Away’ is a show. Everybody knows what it is. ...It’s requisite that that couple have as abrasive and explosive a separation as possible because their coming together is really tough, and if they kind of drifted apart here, who cares if they get back together or not?”

Marielys Molina and Matthew Stockwell Dibble in Twyla Tharp's "Come Fly Away." (Joan Marcus)

Fans of her concert-dance works may miss the stylization — and sophistication — of her more artistic pieces, but Tharp, whose career spans experimental works at Judson Church in the 1960s to ballet troupes, movies and TV, has little patience with being pigeonholed.

“I’ve had so many careers and so many corners turned, that now it’s, okay, which expectation do we have? Are we expecting to see ‘Remove’ from Judson? Are we expecting to see ‘Baker’s Dozen?’ Are we expecting to see a big ballet? What are we expecting here? Could we just look at the stage and forget all that and see what’s there?”

I had to ask Tharp why she comes back so often to Sinatra’s recordings of “My Way” as a resolution — she used it twice in “Nine Sinatra Songs,” and also at the end of “Come Fly Away.” What does she hear in that tune, so schmaltzified by endless wedding deejays?

It turns out the song had become a touchy subject even for Sinatra, as Tharp tells it. She had dinner once with the crooner and his fourth and final wife, Barbara, who said she wouldn’t allow him to sing the song any more, “because it’s about MY way, his way,” Tharp said.

“But I don’t see it that way,” Tharp continued. “I see the ultimate resolution for couples being the situation where each of them is doing it their way, together, and to get there it’s ‘my way.’ Ultimately the couple that is going to make it has had some of the wrenching and had some of the components of all these dances, and is able to express anger and dissatisfaction, along with pleasure, joy and love. But they manage to communicate. His ‘my way’ and her ‘my way’ have found a way to be ‘our way.’”

Mallauri Esquibel and Ron Todorowski in Twyla Tharp's "Come Fly Away." (Joan Marcus)

So the tune gains a moral dimension. “There is a moral dimension, for me, in anything that’s any good,” Tharp said. “In ‘Come Fly Away,’ it’s survival. The fact that these folks go through a shakedown and find a resolution.”

To make the tighter, one-act show that premiered at the Wynn Resort in Las Vegas (and which is the “Come Fly Away” version now touring), Tharp had to make some drastic cuts, including axing a poignant solo — one that was truly incredible to watch, so full of reflection and regret — danced in the Atlanta and Broadway versions by John Selya.

“I had to leave on my cutting-room floor one of my favorite things, which is ‘September of My Youth.’ To move the show along more quickly, and not allow it to ramble or digress into single characters, and hold it to couples,” Tharp said. “That was the equivalent of a monologue. Another reason, frankly, that it got cut is because, basically, nobody could do it but John Selya. John’s a surfer. The rhythm of his movement comes from a place that’s not afraid to be unfamiliar, so he can weave and move his phrases around, which is one of the things that gives it impact. It was gorgeous with John, but ultimately it was an excerptable thing.

“In this kind of exercise, if you can cut it and go on, cut it. It could be cut. It got cut. So,” Tharp sighed, revealing something of the cost of such a decision, “another song went in: ‘Here’s to the Losers.’” This was a suggestion from resort owner Steve Wynn, who favored Sinatra’s gambling songs. Tharp found it was a good match for the show’s dysfunctional lovers Babe and Sid: “Right after she has broken her date’s heart, and takes on this attraction to Sid, she has both in her hands, and she’s the kind of girl that she is, so, here’s to the losers. And she turns them both into losers. That doesn’t exactly bring her close to our heart, but, hello, she’s gorgeous. End of story. Right?”

Another addition to “Come Fly Away” is the song “I Like to Lead When I Dance,” which allowed Tharp to explore some of the fierce emotions in Sinatra’s fiery marriage to actress Ava Gardner. “Although they all are Sinatra,” Tharp said of the men in her show, “the Sid character is the part of him that was the star, that had to be the center of the action. He was all the heat in the world, and when Ava came into the room they had a problem, because the same was true of her. And they both wanted to be on dead center. All the time. So that’s what that relationship was about.

“It becomes clear to us now, which is about right in the middle of the show, that this is a dilemma with these two.”

Tharp came up with a choreographic resolution. “Via the brilliance of physical design,” as she put it, she created a way for them to occupy center simultaneously: “He takes her on his shoulder, he opens out his arms, she’s on a horizontal angle, he turns with her, they’re both on center.”

The company of Twyla Tharp's "Come Fly Away." (Joan Marcus)

As for new projects, she will make another pass at her children’s production, “The Princess and the Goblin,” premiered by the Atlanta Ballet in February. “It’s not done yet. There are several big issues from Atlanta to be resolved. I had a doppelganger in it, and ultimately I think it was a mistake. It’ll be more direct and more functional.” Canada’s Royal Winnipeg Ballet will perform it in October.

I asked her if she people-watches for ideas. She gave me a blank look: “What’s people watch?” she asked. To hang out on a park bench and watch people, I said. “Well, maybe,” Tharp replied, uncertainly, “but I spend most of the time in the studio. I’m the body snatcher, but I do it with dancers. Do I watch dancers as people? Yes, absolutely. Do I watch really good dancers for specifically who they are? Absolutely, because how they move best and how they look best is going to be most familiar to them, and not necessarily to me. So that’s part of my challenge and privilege.”

One thing she does not do is watch the reality-TV competition dance shows — she doesn’t have a TV. “I do not watch television, never have.”

“I see competition kids in auditions sometimes. They have limited techniques, because they are trained to deliver and that’s it. They also don’t understand about transitional moves, and they don’t have a lot of range. And that’s not very helpful for me.”

One more thing: When her new Web site is launched, make sure to click on “Once More Frank,” a piece she made in 1976 for Mikhail Baryshnikov. Tharp showed me a video clip for the new site, of her and the Russian ballet star in the studio, dancing to Sinatra’s “That’s Life” — the same tune used in “Nine Sinatra Songs” and in “Come Fly Away.” In this first bit of choreography for it, you see nothing of the testy relationship of the later versions. There’s just the two dancers, side by side, turning corners, padding around in a loose-jointed, slouchy style, both with shaggy mops of hair swinging over their eyes with each bounce. At the very end, Tharp jumps into a dive and Baryshnikov catches her.

“That was the only part I kept,” Tharp said. The piece was not about tortured romance, but simply “about dancing. But the ending is what made that jump-catch that you see now” in her later works. This clip is the perfect example of how her work evolves through a slow, trial-and-error process.

“That shows you,” Tharp said, snapping her fingers, “it doesn’t happen like this.”

Ramona Kelley and Christopher Vo in Twyla Tharp's "Come Fly Away." (Joan Marcus)