"I laughed," Horner said last week. "I said, 'You don't expect me to swallow that one, do you?' I didn't believe him."
At Dunwoody Village, the retirement community where Horner lives, he is in charge of keeping the piano in tune, said Nancy Morrison, director of community relations.
"We knew he played the piano, but we were all a bit surprised by this," she said.
Horner was born in 1923 in Moravia. In 1942, he and his family were sent to Terezin, a camp northwest of Prague. Terezin was said to have been used by the Germans for propaganda purposes and presented to the public as a model settlement community. Many middle-class residents of Germany and other areas were imprisoned there as were a number of musicians, composers, and other artists.
Horner began playing piano and accordion and got to know composers Gideon Klein and Karel Svenk, he said. Two years later he and his family were sent to the Auschwitz concentration camp in Poland, at which point his father was killed, and he was sentenced to hard labor. After suffering starvation and beatings, Horner was one of thousands of prisoners ordered to make a "death march" to Buchenwald, in Germany.
Horner was freed in 1945 but learned that his mother and sister had died. He threw himself into his studies in Prague, then relocated to Australia to earn his medical degree, specializing in cardiopulmonology.
"It sounds foolish, but I didn't just want to earn a good living," he said. "I wanted to help people. I really loved it. Now I miss it."
After marrying, he and his wife had two sons before moving to the United States in the mid-1960s. He became assistant professor of medicine and director of the cardiopulmonology lab at Yale and later moved to Philadelphia to work at Lankenau Hospital.
Now, Horner is believed to be one of the last remaining survivors of Terezin. For the gala this month, Horner will play two piano pieces that were composed there - works that Horner himself played there 70 years ago.
"It's a tribute to many lives," he said. "It's an interesting story but such a tragic one."