No two Strads are alike, they say, but the violin that Mira Wang reintroduced to the world Monday night is truly special. It was gone for decades, stolen after a concert in 1980, and its owner, Roman Totenberg, died in 2012 thinking it would never be seen again.

At a few minutes after 8 p.m., Wang proved her beloved teacher wrong.

“May he hear the violin tonight,” she told an audience of 200 people at a private club in Manhattan, and then launched into the Ysaÿe Violin Sonata No. 2.

Wang, 49, a masterful soloist who emigrated from China in the 1980s to study with Totenberg, performed a movement that seemed scripted for the instrument, the moment and the player, with shifting tempos, dashing runs and delicate, crying notes. It’s not a piece you can hide behind — and she didn’t.

When Wang was done, she declared, “I’m holding the Totenberg Ames Stradivarius in my hands.”

Such a declaration would have seemed unthinkable as recently as two years ago. Philip Johnson, a talented but erratic younger player, stole the violin after a performance by Totenberg in Cambridge, Mass. He seemed to have gotten away with the crime. For the remainder of Totenberg’s life, memories of the Stradivarius — sparked by old recordings or concert posters — would bring sadness to the normally ebullient master.

Wang’s performance marked perhaps the final chapter in a stunning musical mystery. (As is standard in high-society Manhattan, the private club in which she performed allowed The Washington Post to witness the moment only on the condition that it not be named.) Among the 200 people at the concert were many of the central characters in the happy ending. Christopher McKeough, the FBI agent who helped recover the Strad in 2015, sat on the left side of the room. Bruno Price, the rare-instrument dealer whose shop restored it, took his place across the room. Then there were the three sisters in the second row: Nina, Jill and Amy Totenberg last watched their father perform on the Stradivarius during the waning days of the Carter administration.

They were thrilled to hear the violin reclaimed.

“I think it was better than we expected,” Jill Totenberg said. “Remember, she’s only been with that instrument for a month.”

The Stradivarius, built in 1734, is considered quite rare, as only 500 or so of the 1,000 violins dating before Antonio Stradivari’s death in 1737 have survived. Johnson stole it on May 13, 1980, at the Longy School of Music in Cambridge, Mass., after Totenberg played an all-Mozart recital. He was a suspect at the time, but Johnson was never caught. It wasn’t until 2015, four years after his death of cancer in California, that his ex-wife took the instrument to a dealer to be appraised. It was immediately identified as Totenberg’s violin.

The sisters plan to sell the Stradivarius, but want to make sure that it ends up in the hands of a player instead of tucked away by a wealthy collector. And first, they wanted it to be heard in public again. They knew exactly who should unveil it.

Wang met Totenberg in 1986 at a competition in Poland. With the help of a translator, she wrote Totenberg a letter that led to her being awarded a scholarship to Boston University, where he taught. Wang showed up in the United States speaking no English and with a rickety violin. Totenberg lent her another instrument, and he and his wife, Melanie, gave her a place to stay. At some point, he told her about the stolen Stradivarius.

“He told me of the suspicions, of who took it,” Wang said before the concert. “But of course, it had been so many years, he thought probably it was long gone. He didn’t like to talk about that. Because it would bring him pain, for sure. So we didn’t talk about it too many times.”

Over the years, she remained close, seeing Totenberg every few months and talking to him often. A few days before he died in 2012, she made the trip to Newton, Mass., to sit by his bed and play Bach and Brahms.

“I just wanted him to listen to some music and bring him peace,” Wang said. “There were so many visitors by then. When I first started playing, I saw it in his face.”

The recovery of the Stradivarius has been emotional for the sisters. Amy, a federal judge, found herself moved by the many cards of congratulations from the countless students devoted to her parents. Jill, who runs a public relations firm, joyously toasted along with her sisters with a shot of vodka — Roman’s drink of choice — when the FBI returned the Strad in 2015. Nina, the NPR legal affairs correspondent, found herself having dreams about her father and waking up crying. The Stradivarius brought her back to another time, when they were all so much younger.

“When he died, I was ready for him to die,” she said. “I was very sad, but he got so frail in that last year. And suddenly, I was mourning the death of somebody who was like 50- or 60-something.”

On Monday night, the shift from looking back to looking forward began.

First, Wang played her solo opening. The audience cheered her, but her husband, cellist Jan Vogler, could tell that the moment had been difficult.

“She was very emotional, because of Roman,” he said. “I could see it in her face the first note.”

Then, at 8:15 p.m., she called the four other players from the back of the room to tackle a Mendelssohn string quintet. Together, they offered her mentor his greatest tribute.

When they were done, David Austin, a retired architect in the audience, didn’t say a word about the fascinating mystery that led to the violin’s rediscovery. He had a more important question.

“How could they play those triplets so fast?”

Just like that, Roman Totenberg’s Stradivarius had been reborn as another working instrument. A prized, precious one, of course, but an instrument to be celebrated less for where it had been than for where it might be going.