Question: who sang on the dark side of the moon
[{'answer': 'Pink Floyd', 'provenance': [{'wikipedia_id': '42634', 'title': 'The Dark Side of the Moon', 'start_paragraph_id': 1, 'start_character': 74, 'end_paragraph_id': 1, 'end_character': 84, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]