Question: who played piano on while my guitar gently weeps
[{'answer': 'Paul McCartney', 'provenance': [{'wikipedia_id': '921672', 'title': 'While My Guitar Gently Weeps', 'start_paragraph_id': 3, 'start_character': 209, 'end_paragraph_id': 3, 'end_character': 223, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '921672', 'title': 'While My Guitar Gently Weeps', 'start_paragraph_id': 50, 'start_character': 0, 'end_paragraph_id': 50, 'end_character': 55, 'bleu_score': 0.6803749333171201, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9882873250405583755}, 'section': 'Section::::Personnel.\n'}]}]