Question: who does the theme song for mr pickles
[{'answer': 'Mark Rivers', 'provenance': [{'wikipedia_id': '43371594', 'title': 'Mr. Pickles', 'start_paragraph_id': 34, 'start_character': 12, 'end_paragraph_id': 34, 'end_character': 23, 'bleu_score': 1.0, 'section': 'Section::::Characters.:Additional voices.\n'}]}]