Question: who sang the song man on the silver mountain
[{'answer': 'Rainbow', 'provenance': [{'wikipedia_id': '40212595', 'title': 'Man on the Silver Mountain', 'start_paragraph_id': 1, 'start_character': 52, 'end_paragraph_id': 1, 'end_character': 59, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]