Question: who sang comfortably numb in the movie the departed
[{'answer': 'Roger Waters', 'provenance': [{'wikipedia_id': '544596', 'title': 'Comfortably Numb', 'start_paragraph_id': 1, 'start_character': 329, 'end_paragraph_id': 1, 'end_character': 341, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '544596', 'title': 'Comfortably Numb', 'start_paragraph_id': 20, 'start_character': 0, 'end_paragraph_id': 20, 'end_character': 821, 'bleu_score': 0.949546853413003, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6330530788205666065}, 'section': 'Section::::Live performances.:Roger Waters.\n'}]}]