Question: who sings lead on anna by the beatles
[{'answer': 'John Lennon', 'provenance': [{'wikipedia_id': '2253840', 'title': 'Anna (Go to Him)', 'start_paragraph_id': 4, 'start_character': 257, 'end_paragraph_id': 4, 'end_character': 268, 'bleu_score': 1.0, 'section': 'Section::::Background.\n'}]}]