Question: what is the lead singers name of staind
[{'answer': 'Aaron Lewis', 'provenance': [{'wikipedia_id': '29489', 'title': 'Staind', 'start_paragraph_id': 1, 'start_character': 132, 'end_paragraph_id': 1, 'end_character': 143, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '29489', 'title': 'Staind', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 1271, 'bleu_score': 0.7863485864987391, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8285975678731501821}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '29489', 'title': 'Staind', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['Staind ( ) is an American alternative rock band formed in 1995. The original lineup consisted of lead vocalist and rhythm guitarist Aaron Lewis, lead guitarist Mike Mushok, bassist and backing vocalist Johnny April, and drummer Jon Wysocki.', 'Staind ( ) is an American alternative rock band formed in 1995. The original lineup consisted of lead vocalist and rhythm guitarist Aaron Lewis, lead guitarist Mike Mushok, bassist and backing vocalist Johnny April, and drummer Jon Wysocki.', 'Aaron Lewis']}}]}]