Question: who sang lead vocals on smoke on the water
[{'answer': 'Ian Gillan', 'provenance': [{'wikipedia_id': '356071', 'title': 'Smoke on the Water', 'start_paragraph_id': 3, 'start_character': 389, 'end_paragraph_id': 3, 'end_character': 399, 'bleu_score': 1.0, 'section': 'Section::::Composition.\n'}]}, {'provenance': [{'wikipedia_id': '356071', 'title': 'Smoke on the Water', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 441, 'bleu_score': 0.9237358733926051, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15536900308668512349}, 'section': 'Section::::Composition.\n'}]}]