Question: when did the song a whiter shade of pale come out
[{'answer': '12 May 1967', 'provenance': [{'wikipedia_id': '1369118', 'title': 'A Whiter Shade of Pale', 'start_paragraph_id': 1, 'start_character': 93, 'end_paragraph_id': 1, 'end_character': 104, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1369118', 'title': 'A Whiter Shade of Pale', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 450, 'bleu_score': 0.7848570000574331, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14515909538368233254}, 'section': 'Section::::Abstract.'}]}]