NEW YORK, NY.- Consider the 21 gilded mirrors lining the music room, each more extravagant than the last. Or the Italian monastery table that seats 24, never mind the tapestries, peacock feathers, brass candlesticks and Persian rugs seemingly everywhere.

And did we mention entire suites dedicated to Frank Sinatra and Noël Coward?

Let others embrace minimalism. Good things come in multiples in the waterfront home that Tom Postilio and Mickey Conlon have created for themselves on 2 1/4 acres on the North Shore of Long Island.

Even the house itself, which began life as a single-story Mediterranean-style abode from the 1960s, appears to have adopted the more-is-more mantra, swelling to 10,000 square feet of Spanish Colonial splendor encompassing six bedrooms, five fireplaces, a conservatory, a library and an expansive subterranean level with a screening room, music “archive” and hammered-brass bar presided over by an Al Hirschfeld mural and a portrait of Charles Nelson Riley — on black velvet.

“Too much of a good thing is wonderful,” said Postilio, quoting Mae West by way of Liberace.

The whole enterprise began modestly, though.

Postilio, 54, and Conlon, 47, real estate brokers with a background in show business and a celebrity clientele (including Liza Minnelli, Barry Manilow and Marilyn Horne), had long had a one-bedroom apartment in Manhattan and wanted a place they could escape to on weekends.

They explored the usual haunts: the Hamptons, Connecticut, the upstate New York town of Hudson — wherever they had friends and there was “upside potential,” said Conlon. Then they realized that the village of Nissequogue, not far from where Conlon grew up and Postilio spent his teens, possessed everything they wanted, including dreamy views of Long Island Sound.

“Dorothy had to go to Oz to discover there’s no place like home,” said Postilio, who, like his husband, is an old movie buff.

Conlon’s mother, a real estate agent herself, happened to own the 1960s house, perched on a bluff overlooking the water. She had vague plans to fix it up and retire there someday but she was in her 70s, and already retired. So in 2012, she agreed to sell, for $870,000.

As the new homeowners embarked on a renovation — with the idea of raising ceilings, enlarging windows and bumping out a room toward the water — they encountered structural issues, including a 40-foot crack in the cinder-block foundation. When part of the foundation caved in after a storm, they realized they had to start all over.

That’s when they started to get ambitious.

Because of the site’s proximity to the water, they were required by local zoning to confine themselves to the footprint of the original house. But if they couldn’t build out they could build up, which offered the advantage of more windows and more views — more “upside” and, not incidentally, more room for guests. They could also build down.

At first, ever the real estate professionals, they found themselves making decisions with an eye to resale value. Somewhere along the way they began to embrace the adventure of designing for their own delight. “This is not the house for a broader demographic,” Conlon said.

They were aided and abetted by John Cetra and Nancy J. Ruddy, the married founding principals of the design firm CetraRuddy. The couples had met on a project years earlier and discovered they all loved the 20th-century musical standards collectively known as the Great American Songbook. They became friends.

Cetra, an architect, and Ruddy, a designer, tend to work in a clean, modern style. But like their clients, they are admirers of Addison Mizner, who conjured up spectacular Spanish Colonial Revival estates in southern Florida in the 1920s. They channeled Mizner in their design for the house.

Six years, two contractors and $8 million later, the new stucco home had risen under a clay-tile roof, evoking the past without any of the crankiness of an actual old house.

The double-height foyer has what people in real estate call the “wow factor,” with spiraling columns and a coffered ceiling inscribed with lines from favorite songs. Off it is a hall with a vaulted ceiling.

But the interior is free of fussy woodwork and window treatments. All the better to focus attention on the view — and the owners’ prized possessions.

Postilio, a professional singer before getting into real estate, had acquired a vast collection of Frank Sinatra memorabilia that was stashed in plastic bins in his parents’ basement. Conlon, a former Broadway producer, was practically born collecting — when he was 16 his mother signed a lease so he could open an antiques shop — and today follows online auctions with the ardent attention others devote to sporting events.

That’s how they came to own a 17th-century chest that belonged to Phyllis Diller (whom Postilio opened for in Atlantic City in 1993; the chest is in the foyer). They also have a wrought-iron fire screen from Marlene Dietrich’s Park Avenue apartment (now in their dining room) and Cole Porter’s backgammon set (goes back and forth between the music room and the conservatory — because they use it).

“Having stuff in boxes is no fun,” Conlon said.

The couple got the idea for themed guest quarters from a stay at London’s Savoy hotel, where suites are dedicated to well-known figures, including Winston Churchill and Frank Sinatra.

Their own Sinatra suite has a curvaceous headboard upholstered in moleskin in the singer’s favorite color — orange — flanked by ginger-jar lamps that came from the estate of Sinatra’s first wife and lifelong friend and confidant, Nancy. In the Noël Coward suite, charming landscape oils by the playwright, actor and composer hang on walls and are propped on an easel.

The suite that came together most recently is devoted to entertainer and songwriter Peter Allen. Postilio said he was inspired to embrace his sexuality when he was 20 and heard Allen sing “Love Don’t Need a Reason” and found himself moved to tears by the line “love’s never a crime.” Because Allen was a flamboyant performer who favored flashy costumes, Postilio and Conlon felt his room should be over the top, too.

Its gold-painted wrought iron bed has a purple velvet spread with a silk leopard-print lining. A floor lamp is shaped like a palm tree, with ostrich feathers for foliage. Seashells march across the top edge of a mahogany-and-mother-of-pearl fainting couch upholstered in more velvet, this time pink.

“It may look campy, but everything has meaning to them,” Cetra said about his clients.

The couple, who recently moved their business to Compass, said their land alone has appreciated threefold since their purchase. (“Upside!”) And while they may be persuaded to sell someday, they said they are, for now, hosting friends and family, throwing parties and just generally enjoying their creation.

Still, one guest demurred when offered the opportunity to sleep in the Allen room.

“I’m a gay man,” he said to one of his hosts, “but this is too gay for me.”

This article originally appeared in The New York Times.