Question: who is singing in summer by calvin harris
[{'answer': 'Calvin Harris', 'provenance': [{'wikipedia_id': '42173878', 'title': 'Summer (Calvin Harris song)', 'start_paragraph_id': 0, 'start_character': 8, 'end_paragraph_id': 0, 'end_character': 21, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '42173878', 'title': 'Summer (Calvin Harris song)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 354, 'bleu_score': 0.8297032342727321, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9854144103667785933}, 'section': 'Section::::Abstract.'}]}]