Question: who sang sing me a song mr piano man
[{'answer': 'Billy Joel', 'provenance': [{'wikipedia_id': '1680148', 'title': 'Piano Man (song)', 'start_paragraph_id': 1, 'start_character': 74, 'end_paragraph_id': 1, 'end_character': 84, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]