Question: who created the unique combination of cutting and double backing called the quick mix theory
[{'answer': 'Grandmaster Flash', 'provenance': [{'wikipedia_id': '232674', 'title': 'Turntablism', 'start_paragraph_id': 13, 'start_character': 230, 'end_paragraph_id': 13, 'end_character': 247, 'bleu_score': 1.0, 'section': 'Section::::History.:Hip-Hop.\n'}]}, {'provenance': [{'wikipedia_id': '232674', 'title': 'Turntablism', 'start_paragraph_id': 14, 'start_character': 0, 'end_paragraph_id': 14, 'end_character': 1004, 'bleu_score': 0.9889802957688271, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2541705416489807231}, 'section': 'Section::::History.:Hip-Hop.\n'}]}]