Amnon Weinstein first encountered a violin from the Holocaust 50 years ago. He was a young violin maker in Israel, and a customer brought him an old instrument in terrible condition and wanted it restored.

The customer had played on the violin on the way to the gas chamber, but he survived because the Germans needed him for their death camp orchestra. He hadn't played on it since.

"So I opened the violin, and there inside there [were] ashes," Weinstein says.