Question: who performed at the 2017 super bowl halftime show
[{'answer': 'headlined by Lady Gaga'}, {'provenance': [{'wikipedia_id': '45280343', 'title': 'Super Bowl LI halftime show', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 253, 'bleu_score': 0.68365988062297, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17228179647813142436}, 'section': 'Section::::Abstract.'}]}]