Question: who sang vocals on wish you were here
[{'answer': 'David Gilmour', 'provenance': [{'wikipedia_id': '30220496', 'title': 'Wish You Were Here (Pink Floyd song)', 'start_paragraph_id': 1, 'start_character': 89, 'end_paragraph_id': 1, 'end_character': 102, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '30220496', 'title': 'Wish You Were Here (Pink Floyd song)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 184, 'bleu_score': 0.6005127005315011, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6532756636967131780}, 'section': 'Section::::Abstract.'}]}]