Question: what type of poem is the unquiet grave
[{'answer': 'Ballad', 'provenance': [{'wikipedia_id': '2276272', 'title': 'The Unquiet Grave', 'start_paragraph_id': 1, 'start_character': 225, 'end_paragraph_id': 1, 'end_character': 231, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2276272', 'title': 'The Unquiet Grave', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 411, 'bleu_score': 0.9748377259086851, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15471627025287458592}, 'section': 'Section::::Abstract.'}]}]