Task: Question Generation
Input (English): Chopin made his last public appearance on a concert platform at London's Guildhall on 16 November 1848, when, in a final patriotic gesture, he played for the benefit of Polish refugees. By this time he was very seriously ill, weighing under 99 pounds (i.e. less than 45 kg), and his doctors were aware that his sickness was at a terminal stage.
Output (English): When did Chopin last appear in public?