Question: in a song that is in a meter of four each grouping of four beats is called a
[{'answer': 'metre', 'provenance': [{'wikipedia_id': '84026', 'title': 'Metre (music)', 'start_paragraph_id': 1, 'start_character': 10, 'end_paragraph_id': 1, 'end_character': 15, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '84026', 'title': 'Metre (music)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 210, 'bleu_score': 0.8635707684233571, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6227177725143379686}, 'section': 'Section::::Abstract.'}]}]