Vanessa Hicks isn’t a Halloween person. She has never been into the holiday’s campiness. Yet, Ms. Hicks, an executive coach, has spent thousands of dollars every October for the past 15 years on candy and elaborate decorations outside her home on West 69th Street in Manhattan.

Halloween is a special holiday for many New York City neighborhoods, with city dwellers decking out brownstones and Victorians, rowhouses and high-rises. But West 69th Street, between Broadway and Central Park West on Manhattan’s Upper West Side, transforms into an open-air museum of Halloween art. Part haunted carnival and part design showcase, the scene can include professional aerialists rappelling from brownstones, doormen donning gorilla costumes and aliens dancing under a disco ball.

When Ms. Hicks, 56, moved in 15 years ago, someone from the West 69th Street Block Association explained participation is technically voluntary, but most neighbors don’t dream of opting out. Last year, she collaborated with her 80-year-old neighbor, Irene Pletka, to create a “WITCHES” theme — an acronym for “women in total control of themselves.” Inspired by JD Vance’s “childless cat ladies” comment, the display included a banner featuring Oprah, Julia Child and Emily Dickinson. This year, her theme is Hitchcock films.

Formed in 1969, the block association has nurtured a Halloween tradition dating back to 1971. Each year, its Halloween committee organizes a trick-or-treating affair that draws more than 4,000 children — a celebration many neighbors see as both a community service and a way to bring the block together.

Around 15 years ago, the association began awarding prizes to the top three best-decorated buildings. Now a hallmark of the annual ritual, the competition has created inter-building rivalries, and residents go to great lengths to win.

One Building, 11 Elvis Impersonators

In September, over chocolate chip cookies and cans of LaCroix, the residents of 66 West 69th Street gathered in Lucy Head’s apartment to pick a theme from nine possibilities, including “MoMA” and “Harry Potter,” using the following ranked criteria: Will kids like it, are costumes affordable, and can it win? The group settled on Elvis, with 69.6 percent of the vote. Ms. Head, 41, who is a singer and researcher, bought a bag of Elvis wigs from Abracadabra, a costume store in Chelsea.

By early October, it was time to decide how to decorate and what costumes to buy. This time, the crew gathered in Anthony Bracco’s apartment, and Ms. Head projected her laptop screen onto the TV. With her Canva account open to a mock-up featuring a photo of the building’s exterior with a Vegas backdrop, an Eiffel Tower and the name Elvis in bright red glitter lights, everyone talked over each other about what they did and didn’t like. Finally, they zeroed in on Vegas.

With laptops open as if in a work meeting, Mr. Bracco, 46, a sales adviser at Oscar de la Renta, ordered a red velvet curtain for the front door. Tom Garbett, 29, a photographer for the Brooklyn Nets, ordered a 20-foot backdrop for $250 to hang on the building’s exterior.

Now it was time to assign everyone Elvis iterations: Vegas, Jailhouse Rock, Comeback Special, Blue Hawaii and Sparkly Gold. “I need a fake hairy chest!” said Zoë Thompson, 30, a producer, who settled on Vegas Elvis.

Someone dared to suggest ordering a fog machine, and Mr. Bracco immediately rebuked them. “Every time we’ve tried the fog machine, it has never worked,” yelled Mr. Bracco. “And we tried it on three separate occasions!”

At the close of the meeting, Ms. Head had everyone promise to order their costumes, devise a plan for adding more sideburns to their wigs, and come limber for the next gathering: dance practice.

On Oct. 15 at 8:30 p.m., nine residents gathered to learn a two-minute, 30-second dance routine to a medley of Elvis songs, choreographed by Max Kravchenko, 28, a ballroom dance instructor at Fred Astaire Dance Studios who has lived in the building for two years. Over clips of “Viva Las Vegas,” “Hound Dog,” “A Little Less Conversation” and “Jailhouse Rock,” Mr. Kravchenko shouted cues.

“Sashay! Sashay! Swing the mic,” he said. “With the hip!”

Sweaty and out of breath from 90 minutes of dancing, the crew agreed to have a dress rehearsal on Oct. 23.

“Wait, can you show us the jackhammer? I feel like I’m not getting it,” Ms. Thompson, dressed in a white bell-bottom jumpsuit with flutter sleeves, asked Mr. Kravchenko.

The crew agreed to practice one more time before Halloween, when they will take their show outside to perform on trash cans in front of the building.

69th Street Inspired an Artist

Max Szadek started planning for Halloween last November. He collected paper grocery bags from H-Mart and Pioneer to make paper dresses for the sheep he planned to build from recycled materials for an exhibition he titled “Little Bo Peep Who Lost Her Sheep That Ran Away and Went to the Masquerade.”

Inspired by the Belgian artist Isabelle de Borchgrave, who created historical costumes out of paper recreations, Mr. Szadek, 62, wanted to create an exhibition using mostly paper and recycled materials. A celebrity assistant to Itzhak Perlman, the Israeli-American violinist, Mr. Szadek works out of his office on West 69th Street and lives in Murray Hill, Manhattan. When not on tour with Mr. Perlman, he spent many weekends and evenings working on his Halloween creations.

The four sheep were created to resemble the following: Scarlett O’Hara from the picnic scene in “Gone With the Wind”; Mary Poppins; Truly Scrumptious, a character from the film “Chitty Chitty Bang Bang”; and the Day of the Dead.

Last year, Mr. Szadek, a former costume designer, won the block’s décor contest for his Princess Frog installation, inspired by the “Frog Prince” fairy tale.

“That win pierced my heart,” he said. ​​And yet he felt undeserving and wanted to deliver again this year. He said, “I need to show that I was worthy of the prize.”

Mr. Szadek hand-painted and decoupaged the sheep’s dresses, sealing them with polyurethane after testing nearly a dozen designs. He began making art in 2018, inspired by Halloween on West 69th Street.

“The joy I saw from the kids, the community, and the neighborhood spirit of the street. It’s so great to just do something for the sheer joy of making it,” he said. “Lots of people have said to me, like, ‘Oh, you should put your stuff in a museum.’ And I’m like, ‘I have the greatest exhibit of my life.’”

In 2018, he found out his office building was doing a ghost theme but didn’t need any more items, leaving Mr. Szadek devastated that his various ghost creations were superfluous. His friend Lauren Rick, then a dog walker in the neighborhood, walked him around to five different potential new display spots, from flower beds to open entrances. “She was like a real estate agent,” he said.

Eileen Vazquez, the current block association president, suggested her building, where Mr. Szadek has exhibited his work for the last three years.

The Paskowitz brownstone sits between Broadway and Columbus Avenue. It is the kind of place strangers visit to take their annual Christmas card photos. Neighbors slow down to admire the mums as they walk their dogs.

But inside, Maria Paskowitz is starting to panic. She’s sitting at her computer at her dining room table, which is covered in craft supplies and hand-drawn mock-ups.

It’s early October, and two merlot-colored king sheet sets sewn together cover the living and dining room floors. Furniture is pushed aside.

Ms. Paskowitz, 51, plans to fashion the sheet sets into a flag as part of her Ancient Rome theme. Large sheets of paper are on the floor, filled with fractions written in pencil. To measure a flag 350 inches tall and 250 inches wide, she calculated the ratios between the paper’s measurements and the flag’s size, then transposed them.

“Every year, I’m like, I’m never doing this again. This was a mistake. I’m just gonna throw some cobwebs on the house. And then every year, I don’t follow my own advice, and I do it again,” she said.

Ms. Paskowitz, whose history-loving high schooler plans to dress as Julius Caesar, has just a few weeks left to turn the exterior of the brownstone where she’s lived for the past decade into a colosseum. She is collaborating with her neighbor, Elizabeth Styron, whose children, aged 9, 13 and 17, will dress as gladiators prepared for combat and a chariot race.

In 2015, when they moved to the block, the Paskowitz family kicked things off with a “Ghostbusters” theme, complete with a giant Marshmallow Man bursting from the window, followed by a whimsical Candy Land display for a few years. Later, Ms. Styron discovered their kids attended the same school, and the two teamed up. One year, they recreated “It’s the Great Pumpkin, Charlie Brown,” with over 40 glowing jack-o’-lanterns and the film projected across their houses.

As a kid, Ms. Paskowitz loved doing arts and crafts, but along the way, she lost sight of her creativity. Before becoming a stay-at-home mom, she graduated from M.I.T. and worked in software. Halloween’s endless knitting, painting and ideating helps her keep in touch with her creativity.

“Even though I’m losing my mind sometimes, because there’s a deadline, right? I am enjoying it the whole time. I have this vision in my head. I’m getting all excited about it,” she said.

On a Friday afternoon two weeks before the big day, Ms. Paskowitz set up a folding table on the landing of her home in between two cardboard columns and began setting the scene for a Roman banquet. She placed skeletons in togas and crowns fit for a Roman goddess at the table for a rehearsal dinner of sorts to see how they held up in the wind. Neighbors stopped to take photos and compliment the tableau.

Suddenly, a gust of wind sent a cardboard column tumbling, nearly into a red ceramic amphora. Ms. Paskowitz resolved to put 10-pound weights inside to keep them upright. Her super, Sergio Andrade, 46, helped secure the column to the stairs with fishing wire while she tied down the skeletons to hold them steady.

“Next year, I’ll learn,” she joked.

“You’ll never learn,” a voice from the street said. It was Larry Marx, 84, a former block association president who lived down the street for 40 years.

He said, “The block gets us all.”

For more coverage of neighborhoods that go all out for Halloween, check out this guide.