Question: what are the keys on a piano made of
[{'answer': 'spruce or basswood', 'provenance': [{'wikipedia_id': '23034', 'title': 'Piano', 'start_paragraph_id': 59, 'start_character': 122, 'end_paragraph_id': 59, 'end_character': 140, 'bleu_score': 1.0, 'section': 'Section::::Construction and components.:Keyboard.\n'}]}, {'provenance': [{'wikipedia_id': '23034', 'title': 'Piano', 'start_paragraph_id': 59, 'start_character': 0, 'end_paragraph_id': 59, 'end_character': 700, 'bleu_score': 0.9829771687435411, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13483021567637184730}, 'section': 'Section::::Construction and components.:Keyboard.\n'}]}]