On Dec. 16, 2016, the day before their anniversary as a couple, Ms. Basile had been writing a paper all day and into the evening in their new apartment when Mr. Smith asked if she could take a break at midnight for Champagne. She was expecting a low-key anniversary toast, but Mr. Smith had a better idea.

“It was midnight and he was getting the Champagne, and he said, ‘Why don’t we play the music ball?’” she said. Years earlier, Ms. Basile had given him a wooden sphere that, when wound with a key, plays a tune from “The Magic Flute,” a favorite opera. Ms. Basile grabbed the ball off a bookshelf. As she was about to wind it up, she found, around the key, an Art Deco ring from the 1930s that Mr. Smith had bought at Erie Basin, a Brooklyn shop Ms. Basile loves.

“I was so surprised,” she said. As “The Magic Flute” played, Mr. Smith proposed. She said yes instantly.

On March 10, Ms. Basile and Mr. Smith were married before 154 guests at the Brooklyn Winery, not far from where they fell in love. Ms. Basile, in a full-length fitted lace dress with a high neck from Shareen Bridal, walked down the aisle with her father. Mr. Smith’s sister, Heather Hussar, who became a marriage officiant via the City of New York for the occasion, led a short ceremony punctuated by three poetry readings. (One, “Dos Palabras,” was read in Spanish and English.)

Just after the ceremony, Mr. Smith and Ms. Basile mingled with family and friends as the Respect Sextet, the band of his former roommates, played selections that included “Hello Mary Lou” and “Campiña,” an Afro-Cuban jazz number with cha-cha leanings.

The newlyweds had been planning a first dance post-dinner to the soul hit “I’ve Been Loving You Too Long,” played by a D.J., but the lure of “Campina” proved too enticing. Mr. Smith cut in to his wife’s dance circle and the couple showed off what looked like well-practiced moves to cheers and wolf whistles.

Later, Ms. Armendariz pointed out that her granddaughter and Mr. Smith were clearly made for each other. Also that it pays to believe in serendipity, especially in New York apartment buildings. “You never know when you’re going to meet somebody and your life will change,” she said.