Question: who established the singing style known as crooning
[{'answer': 'Al Bowlly', 'provenance': [{'wikipedia_id': '1344605', 'title': 'Crooner', 'start_paragraph_id': 3, 'start_character': 339, 'end_paragraph_id': 3, 'end_character': 348, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'answer': 'Gene Austin', 'provenance': [{'wikipedia_id': '1344605', 'title': 'Crooner', 'start_paragraph_id': 3, 'start_character': 350, 'end_paragraph_id': 3, 'end_character': 361, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'answer': 'Art Gillham', 'provenance': [{'wikipedia_id': '1344605', 'title': 'Crooner', 'start_paragraph_id': 3, 'start_character': 363, 'end_paragraph_id': 3, 'end_character': 374, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'answer': 'Vaughn De Leath', 'provenance': [{'wikipedia_id': '1344605', 'title': 'Crooner', 'start_paragraph_id': 3, 'start_character': 409, 'end_paragraph_id': 3, 'end_character': 424, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '1344605', 'title': 'Crooner', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 596, 'bleu_score': 0.9802931511945101, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13219196451436794644}, 'section': 'Section::::History.\n'}]}]