Question: who sang backup vocals on do the bartman from the simpsons
[{'answer': 'Michael Jackson', 'provenance': [{'wikipedia_id': '2105177', 'title': 'Do the Bartman', 'start_paragraph_id': 1, 'start_character': 207, 'end_paragraph_id': 1, 'end_character': 222, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Dan Castellaneta', 'provenance': [{'wikipedia_id': '2105177', 'title': 'Do the Bartman', 'start_paragraph_id': 1, 'start_character': 257, 'end_paragraph_id': 1, 'end_character': 273, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2105177', 'title': 'Do the Bartman', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 415, 'bleu_score': 0.970362113628587, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2503076949532254156}, 'section': 'Section::::Abstract.'}]}]