Question: who sang lead on almost cut my hair
[{'answer': 'David Crosby', 'provenance': [{'wikipedia_id': '52529095', 'title': 'Almost Cut My Hair', 'start_paragraph_id': 2, 'start_character': 177, 'end_paragraph_id': 2, 'end_character': 189, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '52529095', 'title': 'Almost Cut My Hair', 'start_paragraph_id': 8, 'start_character': 0, 'end_paragraph_id': 8, 'end_character': 53, 'bleu_score': 0.6803749333171201, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16977489853661073625}, 'section': 'Section::::Personnel.\n'}]}]