Question: who sang the theme song on the jeffersons
[{'answer': "Ja'net Dubois", 'provenance': [{'wikipedia_id': '477579', 'title': 'The Jeffersons', 'start_paragraph_id': 74, 'start_character': 0, 'end_paragraph_id': 74, 'end_character': 13, 'bleu_score': 1.0, 'section': 'Section::::Theme song.\n'}]}, {'provenance': [{'wikipedia_id': '477579', 'title': 'The Jeffersons', 'start_paragraph_id': 74, 'start_character': 0, 'end_paragraph_id': 74, 'end_character': 190, 'bleu_score': 0.533209913445099, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8073064893449316952}, 'section': 'Section::::Theme song.\n'}]}]