Question: who sang best things in life are free
[{'answer': 'Luther Vandross', 'provenance': [{'wikipedia_id': '1685824', 'title': 'The Best Things in Life Are Free', 'start_paragraph_id': 1, 'start_character': 87, 'end_paragraph_id': 1, 'end_character': 102, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Janet Jackson', 'provenance': [{'wikipedia_id': '1685824', 'title': 'The Best Things in Life Are Free', 'start_paragraph_id': 1, 'start_character': 107, 'end_paragraph_id': 1, 'end_character': 120, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1685824', 'title': 'The Best Things in Life Are Free', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 403, 'bleu_score': 0.5018894155601711, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5314740682576655990}, 'section': 'Section::::Abstract.'}]}]