NEW YORK – Seventeen years later, the debate around “The Sopranos” finale goes on (and on and on and on).

In “Wise Guy,” a new documentary that premiered at Tribeca Festival late Thursday night, series creator David Chase continues to stir the pot about the HBO drama’s famously ambiguous ending.

In the last section of the doc, Chase breaks down the finale at length. He was heavily inspired by the end of Stanley Kubrick’s 1968 masterpiece “2001: A Space Odyssey” and how astronaut Dave Bowman (Keir Dullea) encounters different ages of himself. Chase attempts to mirror that with New Jersey mobster Tony Soprano (James Gandolfini), who throughout the episode, continually walks into his own POV shots.

“It makes me think of death,” Chase says in the documentary. “There’s something mesmerizing about it.”

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Despite pushback from the writers’ room, Chase chose Journey’s 1981 anthem “Don’t Stop Believin’” as the final song because of its lyrics. (“You may not go on, but the universe does,” he explains.) He initially envisioned the ending as an inverse of the opening credits: Tony driving through the Lincoln Tunnel into Manhattan, where he heads to a meeting that “doesn’t go well.”

But he eventually landed on the scene at Holsten’s diner, where Tony meets wife Carmela (Edie Falco) and son A.J. (Robert Iler). As the music plays and daughter Meadow (Jamie-Lynn Sigler) struggles to parallel park outside, a man glances at Tony and goes into the bathroom. Like in “The Godfather,” does he grab a gun and shoot Tony? Or does Meadow simply walk into the restaurant, where they all proceed to have a nice family dinner?

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As we all know, the screen cuts to black at the last second, giving the audience no easy closure. In “Wise Guy,” the cast says they had no idea how the show was going to end before it aired. Even Gandolfini was left confused: Lorraine Bracco, who plays therapist Dr. Melfi, watched the episode with him and said “he was in shock.”

Chase says the ending is whatever viewers want it to be. (And frankly, isn’t it boring when everything gets neatly wrapped up?) But then, he mischievously references an early "Sopranos" episode, in which Meadow helps A.J. with his homework. Attempting to interpret a Robert Frost poem, A.J. asks her, “I thought black meant death?”

So does that mean Chase telegraphed the series finale all the way back in Season 3? “People will say, ‘There! He admitted that Tony died!’” he says with a laugh. “The truth is…,” he begins, before the documentary cuts to black and the end credits roll.

James Gandolfini had to go 'painful' places to play Tony Soprano

For “Sopranos” devotees, the greatest joy of “Wise Guy” is the sheer amount of behind-the-scenes footage. We get to see audition tapes from nearly every cast member, including fan favorites Michael Imperioli (Christopher), Drea de Matteo (Adriana) and Nancy Marchand (Livia). There’s even a clip of Steven Van Zandt auditioning to play Tony, before Chase wrote him the role of right-hand man Silvio.

Many of the doc’s revelations will be familiar to longtime fans: how de Matteo landed her part by the drawn-out way she said “ow,” or how Chase initially envisioned “Sopranos” as a feature film starring Robert De Niro and Anne Bancroft. Matthew Weiner also got hired as a writer after sending Chase his unproduced script for a little series now known as “Mad Men.”

But the documentary’s most moving section is devoted to Gandolfini, who died of a heart attack in 2013 at age 51, six years after “Sopranos” ended its six-season run. The film unearths archival footage of Gandolfini goofing off between takes with Bracco, and details how he gave his castmates $30,000 each after he negotiated a significant pay raise. “He was a very good, kindhearted man,” Falco recalls. But, she says, the role “may have taken a toll on him.”

To portray Tony, “he had to go places that were destructive to him, and painful for him,” Chase says. Before shooting Tony's more violent scenes, Gandolfini would purposefully deprive himself of sleep for days beforehand, or walk around with rocks in his shoes in order to get angry. He would bruise his hands hitting the inside of Tony’s car, and allegedly threatened to quit the show nearly every other day.

According to his co-stars, Gandolfini would often not show up to work if they stayed out late drinking together the night before. In the documentary, former HBO head Chris Albrecht says he once tried to stage an intervention, encouraging the actor to go to rehab. But when he realized what was happening, Gandolfini apparently yelled “Fire me!” and walked out.

The cast gets emotional remembering Gandolfini, as well as late co-star Tony Sirico, who played Paulie and died in 2022. More than a dozen “Sopranos” writers and actors reunited for a post-screening Q&A at the Beacon Theatre with director Alex Gibney, where they reiterated that they’re still a family to this day.

Growing up on set, “it was home,” Sigler said tearfully. “A lot of life happened in those 10 years. No matter what, that set was home and the people up here were home. They accepted you, and loved you no matter what. It was a privilege, and an honor, and it greatly shaped who I am today.”

“Wise Guy” will be released by HBO later this year. Tribeca Festival runs through June 16.