Question: who sang it's so hard to say goodbye to yesterday
[{'answer': 'G.C. Cameron', 'provenance': [{'wikipedia_id': '7195536', 'title': "It's So Hard to Say Goodbye to Yesterday", 'start_paragraph_id': 1, 'start_character': 231, 'end_paragraph_id': 1, 'end_character': 243, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '7195536', 'title': "It's So Hard to Say Goodbye to Yesterday", 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 510, 'bleu_score': 0.978138775770484, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3965317228052400377}, 'section': 'Section::::Abstract.'}]}]