Question: who sings with bing crosby in white christmas
[{'answer': 'the Ken Darby Singers', 'provenance': [{'wikipedia_id': '2817215', 'title': 'White Christmas (song)', 'start_paragraph_id': 5, 'start_character': 362, 'end_paragraph_id': 5, 'end_character': 383, 'bleu_score': 1.0, 'section': 'Section::::Bing Crosby version.\n'}]}, {'provenance': [{'wikipedia_id': '2817215', 'title': 'White Christmas (song)', 'start_paragraph_id': 5, 'start_character': 0, 'end_paragraph_id': 5, 'end_character': 822, 'bleu_score': 0.9469616891680981, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2371780859348756057}, 'section': 'Section::::Bing Crosby version.\n'}]}]