Question: who sings oh lord won't you buy me a mercedes benz
[{'answer': 'Janis Joplin', 'provenance': [{'wikipedia_id': '3342017', 'title': 'Mercedes Benz (song)', 'start_paragraph_id': 1, 'start_character': 58, 'end_paragraph_id': 1, 'end_character': 70, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '3342017', 'title': 'Mercedes Benz (song)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 509, 'bleu_score': 0.9788329837059241, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6940055074097018413}, 'section': 'Section::::Abstract.'}]}]