Question: who sings the song grease is the word
[{'answer': 'Frankie Valli', 'provenance': [{'wikipedia_id': '9324701', 'title': 'Grease (song)', 'start_paragraph_id': 1, 'start_character': 58, 'end_paragraph_id': 1, 'end_character': 71, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]