The logistics of his professional and personal lives rival the complexity of the giant kidney-swap diagrams that decorate his office: arrows zigzagging from one box to another, each box representing another life.
This month and next, for instance, his wife is in Nashville, Tenn.; Ankara, Turkey; Cincinnati; and Warsaw, Poland. Montgomery plans to join her in several cities and has speaking engagements in Boston, Italy and San Diego, to say nothing of the Bonnaroo rock concert in Manchester, Tenn., which Graves is not attending.
Graves interrupted a trip to Eastern Europe last winter to watch her then 5-year-old daughter Ella in a dance recital in Montgomery County and attend a Hopkins event. Then she flew back to continue her performance tour.
Ella is Graves' daughter from a previous marriage. Montgomery was married in his early 20s and has two children from that marriage — one in college, one in high school — and a little boy from a relationship that unfolded when Montgomery was separated from his first wife.
Montgomery and Graves, an imposing, elegant woman raised in Washington, say their first marriages were casualties of their intense focus on their work and that they mean to not have it happen again. Sometimes they join each other on the road. They check in a lot by phone and e-mail.
Next month in Warsaw, Graves will reprise the role of Carmen, the Gypsy, for which she's become famous. Suitably, she and Montgomery met on a United Airlines flight out of Washington Dulles International in June 2006. She and Ella were heading back to Paris, where she lived. He had a connecting flight in Paris en route to a speaking engagement in Sardinia.
In the terminal, he had noticed the stunning woman in a black-and-white print dress. Graves hadn't noticed him until she and Ella sat next to him. He'd planned to spend the flight organizing slides for his talk, but when the battery on Ella's laptop died and with it the DVD she was watching, Montgomery spared Graves a small crisis by volunteering his laptop. They started talking.
"I was touched by his openness and generosity," Graves said. By the time the flight ended, they knew quite a bit about each other. She told him that she was raised without a father; he told her about being apart from his children.
"He shared some insight on what it was like to be a father," Graves said.
"I told everyone about this encounter," she said. "I said, 'I met the most fascinating man.'"
Five days later, they saw each other again when he stopped in Paris on his way back from Sardinia.
"I knew she was going to be someone who would be very important in my life, but I didn't know what," Montgomery said.
The connection was sustained through visits, e-mail, phone calls. Graves moved to the United States, and last summer they were married.
Saying they were merely "married" seems a bit like saying Queen Elizabeth "took office." It was a production of operatic proportions. In June, there was a family ceremony in a small chapel at the National Cathedral. In August, they indulged Montgomery's longtime enthusiasm for African culture by traveling to Kenya for an all-day ceremony among the Masai tribe, in which they were draped in multicolored traditional garb and had their faces daubed with red paint made of ochre and animal fat. In mid-September, their five-day blowout included another ceremony at the National Cathedral, this one for 150 guests, preceded by a party for more than 100 people at an airplane hangar in Leesburg, Va., featuring the Brazilian Girls, the style-blending electronic dance music trio that is one of Montgomery's favorite bands. Montgomery is said to have danced with abandon.
"Denyce doesn't do anything small," Montgomery said. But the Africa part was his idea.
One late afternoon in December, Graves called Montgomery at Hopkins from Slovenia, where she had finished her day's rehearsals for a performance at the Ljubljana Opera House. She just wanted to say goodnight, to see how Montgomery's day was going. He couldn't answer the phone, though, as he was in Operating Room No. 1 in the Carnegie Building, up to his wrists in the abdomen of Wendy Crowder, a 40-year-old woman from Dunnsville, Va.
A nurse picked up the phone from the shelf in the operating room where Montgomery had placed it more than two hours before. He was busy chasing tiny blood leaks on the surface of Crowder's newly transplanted kidney with a cauterizing instrument, raising an aroma of cooking meat.