Question: What American singer, film actor and comedian, suddenly stood up during a performance of Gershwin's Liza (All the Clouds'll Roll Away) and started singing?
{'answer': 'Al Jolson', 'supporting_facts': [["Liza (All the Clouds'll Roll Away)", 0], ["Liza (All the Clouds'll Roll Away)", 3], ['Al Jolson', 0]]}