Question: who sings the theme song for that 70's show
[{'answer': 'Todd Griffin', 'provenance': [{'wikipedia_id': '274551', 'title': "That '70s Show", 'start_paragraph_id': 40, 'start_character': 99, 'end_paragraph_id': 40, 'end_character': 111, 'bleu_score': 1.0, 'section': 'Section::::Production.:Opening.:Theme song.\n'}]}, {'answer': 'Cheap Trick', 'provenance': [{'wikipedia_id': '274551', 'title': "That '70s Show", 'start_paragraph_id': 40, 'start_character': 241, 'end_paragraph_id': 40, 'end_character': 252, 'bleu_score': 1.0, 'section': 'Section::::Production.:Opening.:Theme song.\n'}]}]