Question: who sang r o c k in the usa
[{'answer': 'John Mellencamp', 'provenance': [{'wikipedia_id': '29515957', 'title': 'R.O.C.K. in the U.S.A.', 'start_paragraph_id': 1, 'start_character': 101, 'end_paragraph_id': 1, 'end_character': 116, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '29515957', 'title': 'R.O.C.K. in the U.S.A.', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 250, 'bleu_score': 0.957870874785216, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4117059658329052836}, 'section': 'Section::::Abstract.'}]}]