Question: who sang how long has this been going on song
[{'answer': 'Ace', 'provenance': [{'wikipedia_id': '6135138', 'title': 'How Long (Ace song)', 'start_paragraph_id': 0, 'start_character': 10, 'end_paragraph_id': 0, 'end_character': 13, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '6135138', 'title': 'How Long (Ace song)', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 0, 'bleu_score': 1.0, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3948857397687067756}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '6135138', 'title': 'How Long (Ace song)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 165, 'bleu_score': 0.791537399130509, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3948857397687067756}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '6135138', 'title': 'How Long (Ace song)', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['"How Long" is a 1975 song by the British group Ace from their album "Five-A-Side".', 'How Long" is a 1975 song by the British group Ace from their album "Five-A-Side"', '"How Long" is a 1975 song by the British group Ace from their album "Five-A-Side". It reached No. 3 in the US and Canadian charts, and No. 20 in the UK Singles Chart.']}}]}, {'provenance': [{'wikipedia_id': '6135138', 'title': 'How Long (Ace song)', 'section': 'Section::::Abstract.', 'start_paragraph_id': 2, 'end_paragraph_id': 2, 'meta': {'evidence_span': ['"How Long" is a 1975 song by the British group Ace from their album "Five-A-Side".', '"How Long" is a 1975 song by the British group Ace from their album "Five-A-Side".', '"How Long" is a 1975 song by the British group Ace from their album "Five-A-Side".']}}]}]