Question: who sings the only fools and horses theme song
[{'answer': 'John Sullivan', 'provenance': [{'wikipedia_id': '200842', 'title': 'Only Fools and Horses', 'start_paragraph_id': 1, 'start_character': 76, 'end_paragraph_id': 1, 'end_character': 89, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '200842', 'title': 'Only Fools and Horses', 'start_paragraph_id': 43, 'start_character': 0, 'end_paragraph_id': 43, 'end_character': 1227, 'bleu_score': 0.867217693576494, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11420458481566874072}, 'section': 'Section::::Production.:Theme music and titles.\n'}]}]