Question: who sings the theme song to one day at a time
[{'answer': 'Polly Cutter', 'provenance': [{'wikipedia_id': '801671', 'title': 'One Day at a Time', 'start_paragraph_id': 12, 'start_character': 167, 'end_paragraph_id': 12, 'end_character': 179, 'bleu_score': 1.0, 'section': 'Section::::Production.:Theme song and opening credits.\n'}]}]