Question: when was the first rock and roll song made
[{'answer': '1940s', 'provenance': [{'wikipedia_id': '944646', 'title': 'Origins of rock and roll', 'start_paragraph_id': 1, 'start_character': 161, 'end_paragraph_id': 1, 'end_character': 166, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '944646', 'title': 'Origins of rock and roll', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 96, 'bleu_score': 0.8914703664390791, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7893749756397350922}, 'section': 'Section::::Abstract.'}]}]