Question: who's the singer in avicii hey brother
[{'answer': 'American bluegrass singer Dan Tyminski', 'provenance': [{'wikipedia_id': '40708971', 'title': 'Hey Brother', 'start_paragraph_id': 1, 'start_character': 115, 'end_paragraph_id': 1, 'end_character': 153, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '40708971', 'title': 'Hey Brother', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 330, 'bleu_score': 0.962600167205617, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10739120078448909327}, 'section': 'Section::::Abstract.'}]}]