The best film among the onslaught of works on the 10th anniversary of 9/11 is one by a first time documentary filmmaker that begins to scratch the surface of the wholesale jolt in the national psyche that occurred – and shows a way that it can be slowly healed.

It’s a bit of a miracle since Jim Whitaker’s “Rebirth” (Showtime, 9 p.m.) began as a cold film of time lapse photography showing the progress of the building of the still unfinished One World Trade Center at Ground Zero.

While filming that, he began to include interviews with 10 people directly impacted by the event. And as the years went on with his construction photography, he’d check in with the people. Eventually, their harrowing and emotional stories began to have something in them that might not be apparent in one or two interviews: the possibility of change, a healing from the scarring of the day, the opportunity to maybe move.

It wouldn’t have happened if Whitaker hadn’t kept filming and his subjects didn’t keep talking. And not all of them did.

“One dropped out after the first year,” he said.

And once that happened, he figured that the film would have more of an impact with even fewer subjects.

“Based on the central idea of the site and the idea of loss and the idea of grief and healing,” he says, “the five remaining were the ones that felt like they were the most kind of appropriate for what the film was really speaking to me about, which was the grieving process, the healing process, and the hopeful process of getting beyond where both the subjects were and also where the site was.”

And while footage of the construction progress remained a part of the film, its growth became a metaphor for the wounded people who also grew over the years.

It started, he said, “to become a kind of a meditation of a combination of the two of those things.”

And with the addition of a score by Philip Glass, it became mesmerizing.

For the participants, the film became a form of therapy. Tanya Villanueva-Tapper, who lost her husband, Sergio, a firefighter.

“I always called Jim ‘Dr. Jim’ because the way the interview space was set up, it was just free of distractions and just black screens,” she says. “And he was never pushy with his questions. He kind of just sat there like a therapist. So I would go on these stream of consciousness kinds of thoughts about what grief was like for that particular year.

She says she got involved for a couple of reasons.

“When I signed on, it was to share Sergio’s story in a personal to give a personal connection to September 11th, because I also realized, too, that it was a historical event,” Villanueva-Tapper says. “It was that important that people knew, 50 years from now, what happened that day. So when I was approached for the project, I was like: This is a good way for me to kind of give a testimony on behalf of Sergio.”

“Not once did I ever think that I made a mistake in joining this project,” said another participant, Tim Brown, a member of the New York Fire department Special Operations Command that lost 93 people alone.

“From the beginning, I believed I believed in Jim’s vision, and the further down the road we got and the closer that we got with Jim, the more powerful it became for me,” Brown says.

It was also a way to show at the end what his friend who died was like and become a testimony to the daughter he left behind.

For Whitaker, who had lost his mother six months before 9/11 and was dealing with his own grief, he says “I hope one of the gifts of the film is that by being in it on a year by year basis with the participants in the film, that you can experience the hard parts.”

Whitaker’s dream was to get Glass to do the score. “I’d always thought that he would be incredible for the film. He has a history of doing time lapse, an amazing history of bringing emotionality to that.”

By chance he ran into the composer and had his first screening of the footage for him, which he liked and agreed to score.

The resulting music, Whitaker says, was beautiful and emotional “in the way that it worked with the time lapse, but also with the hopefulness and empathy with the subjects and the strength of its purpose. He’s very good at kind of creating a sense of purpose and drive with the film, and I think he understood that that was what the film was about. It’s about where we go, the hopefulness, where we get to, how we get beyond, and he understood that right away.”

Whitaker hopes to keep updating the story of the Freedom Tower and of his five subjects at least until the construction project is finished.

Speaking of “Rebirth” as it is now, he says, “I love that it’s a hopeful time capsule, and I think it has its own life in being what it is. It’s 10 years of our history and, I think, 10 years ultimately with hope, and I’m open to it but don’t really know. Of course, I could be open to it, but then they have to be open to it. So we’ll see. We’ll see.”

“Rebirth” premieres on Showtime Sept. 11 at 9 p.m.