Question: what type of music is system of a down
[{'answer': 'heavy metal', 'provenance': [{'wikipedia_id': '28715', 'title': 'System of a Down', 'start_paragraph_id': 1, 'start_character': 23, 'end_paragraph_id': 1, 'end_character': 34, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '28715', 'title': 'System of a Down', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 249, 'bleu_score': 0.7556276636317011, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14281689476454137607}, 'section': 'Section::::Abstract.'}]}]