Question: who sang lead vocals on do it again by steely dan
[{'answer': 'Donald Fagen', 'provenance': [{'wikipedia_id': '7178093', 'title': 'Do It Again (Steely Dan song)', 'start_paragraph_id': 1, 'start_character': 54, 'end_paragraph_id': 1, 'end_character': 66, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]