Fifty years ago this week, Duke Ellington and his band played in a concert he later called one of the most memorable of his life. The performance was in Kabul, in Afghanistan, and even though Ellington was at the height of his fame, almost all traces of it have been lost. For the organiser, Faiz Khairzada, and hundreds of Afghans in the audience, the concert was a high point of the early 1960s. "It was very exciting for me to have him in Kabul," says Khairzada, then head of Afghanistan's cultural affairs organisation. It was he who met Ellington at...