On New Year’s Eve, San Francisco will tip its cap for the last time to “Beach Blanket Babylon.”

After 45 years of mad-hatted frivolity, the musical revue launched by the late Steve Silver will close for good at its North Beach home, Club Fugazi, wrapping up one of the greatest — and longest — runs in American theater history.

Jo Schuman Silver, who has overseen the show ever since her husband’s death in 1995, said now was the time to fold.

“About three years ago I just felt the show’s on top, the best it’s ever been, and it’s the right time to say goodbye,” she said. “I definitely struggled, but I thought in the end right now it feels like the right thing to do.”

The campy spectacle has always been framed around the story of Snow White (sans dwarves) on a search for true love. Along the way she encounters a fabulously fey King Louis XIV and, depending on what decade you’re in, outlandish portrayals of Bill Clinton, Barack Obama, a shotgun-toting Dick Cheney, Kim Jong-un or, most recently, a wayward PG&E repairman, all of them belting out the hits and donning sky-high wigs and kooky hats.

How kooky? The show’s iconic San Francisco skyline hat worn in the finale is 14 feet tall, 9 feet wide, 3 feet deep and weighs more than 250 pounds. Heavy indeed is the head that wears that crown.

And if you don’t get a seat for one of the remaining shows, you’ll miss out on the “Sound of Music”-inspired parody of the current first family, in which Captain Von Trump sings “Let Me Entertain You.” It’s yuge!

Schuman Silver announced the closure in April, but now that the final show is around the corner, she admits to bittersweet feelings. After entertaining millions of tourists and locals in more than 17,000 performances, she and her cast and crew still can’t believe it’s nearly curtains for “Beach Blanket Babylon.”

“Acceptance is a fluid thing,” said Shawna Ferris McNulty, a Bay Area native who has played Snow White (and other characters) for more than 15 years. “It’s like processing grief. People do it at their own pace. The ultimate thing now is to cherish what we have left.”

Though aiming for universal appeal, Silver and his successors, including Schuman Silver and longtime director Kenny Mazlow, couldn’t help injecting a healthy dose of Jewish humor into BBB. Silver identified as Jewish and was the original source of the show’s wicked admixture of Jewish-gay-Broadway humor.

Spoofs of Barbra Streisand and merrily dancing Hasids aside, the ever-evolving show has always employed a sly, wry and deliciously cutting form of satirical comedy, riffing on pop culture, politics and celebrity.

It helped that Silver liked to say “yes” to his trusted cast and crew.

“Steve liked to push the envelope,” remembers Mazlow, whose grandfather was an Orthodox cantor. “The show does have a sense of improv, though there is a script that needs to be followed. If he saw something he liked, he’d put it in. We once had an actress [playing Dorothy from “The Wizard of Oz”] who went up to Steve and asked him if she could do a rap. He said, ‘Well, try it.’ The audience went crazy. He was open to anything.”

Born in San Francisco in 1944, Silver earned an MFA at San Jose State University and immediately plunged into creating street theater. He opened “Beach Blanket Babylon” in North Beach on June 7, 1974, for what he thought would be nothing more than a six-week run.

When it came to the show’s signature hats and wigs, turns out necessity was the mother of invention. The original theater that mounted the show the first year, the Savoy Tivoli, had a narrow stage and high ceilings, so Silver dreamed up the high hats to fill space. In 1975, “Beach Blanket Babylon” moved to at Club Fugazi.

As the show built momentum, it not only sold out every performance, in the 1980s it hit the road, with runs in London and Las Vegas. Everyone from Queen Elizabeth II to David Bowie, Michael Tilson Thomas and Robin Williams took in the show over the years.

“You come in and experience joy for an hour and a half,” said Mazlow. “That’s what it is: a visual smorgasbord of the brilliance of [Silver’s] creative mind. When you walk into this elegant theater and all of a sudden this train comes at you, you go ‘Oh my God.’ There’s nothing like ‘Beach Blanket Babylon.’ It’s its own entity.”

Silver went global when he cooked up the now-notorious opening number of the 1989 Oscars, which featured Snow White in the arms of actor Rob Lowe. The sequence famously flopped, though it turned out to be a mere blip in his career.

After Silver died, Schuman Silver took over the show. In 2002 she established the Steve Silver Foundation and its Scholarship for the Arts, which each year awards Bay Area high school seniors who share a passion for the performing arts.

The foundation also has given grants to the San Francisco Museum of Modern Art, the San Francisco Public Library, the Ruth Asawa San Francisco School of the Arts, the Make-a-Wish Foundation, Zuckerberg San Francisco General Hospital and Trauma Center, St. Anthony Foundation, Grace Cathedral and the National AIDS Memorial Grove. Even after the show closes, the Foundation and its work will continue.

“Steve was an incredibly philanthropic man, and so is Jo,” said Mazlow. “She created the scholarship for the high school students, which is a wonderful way to give back. The one thing Steve felt is that you take nothing for granted; that this could all be taken away tomorrow. Part of being grateful to the community for supporting the show was to give back to charitable causes. Steve took tremendous pride in being able to give back to the city.”

And to think it all started in 1974 on a shoestring budget and a satirical, nothing-is-sacred sense of humor.

“It’s a very talented group of people,” Mazlow added. “Jo loved the show first and foremost from the very first time she saw it. She loved Steve, and the continuation of the show was for all the right reasons. She wanted to continue his vision because outside of her love for him, she wanted to allow the world to still benefit from this jewel.”

As “Beach Blanket Babylon” became an institution, its signature hats, wigs and costumes occasionally were put on display in museum galleries and even in City Hall. With the show closing, those artifacts loom large in Schuman Silver’s planning.

“It will be a full-time job,” she said. “We really want to preserve a lot of the costumes, the hats, everything Steve had designed. Right after we close, we’re going to visit a lot of museums. We have so much stuff, and it’s all in such great condition. That’s going to be fun for us.”

Meanwhile, everyone is gearing up to say goodbye.

“I hope people just remember how one-of-a-kind it was, such an institution,” said McNulty, who admits she’s not even sure she’ll be able to snag a ticket for her husband on closing night. “It’s sad to see it go, but it’s nice to see a packed house every night.”

She and other insiders say the final show will be special, with old characters returning to the stage, as well as some surprises they are keeping under their hats for now.

“What I’m really sad about is how many people will not be able to see the show,” said Schuman Silver about future generations. “But it has to end sometime. I’m so proud of the show and everybody who’s worked on it.”

Mazlow, who has been with the show for nearly 30 years, is sad, too, but looks on the bright side. “Change is good. It pushes people,” he said. “It might be a very Jewish way of thinking, but I always think everything is meant to be.”