Question: who did richard pryor play in lady sings the blues
[{'answer': 'Piano Man', 'provenance': [{'wikipedia_id': '225459', 'title': 'Lady Sings the Blues (film)', 'start_paragraph_id': 5, 'start_character': 170, 'end_paragraph_id': 5, 'end_character': 179, 'bleu_score': 1.0, 'section': 'Section::::Plot.\n'}]}, {'provenance': [{'wikipedia_id': '225459', 'title': 'Lady Sings the Blues (film)', 'start_paragraph_id': 15, 'start_character': 0, 'end_paragraph_id': 15, 'end_character': 38, 'bleu_score': 0.6147881529512641, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3104890333052039455}, 'section': 'Section::::Cast.\n'}]}]