Question: when did mozart compose his first piece of music
[{'answer': 'age of five', 'provenance': [{'wikipedia_id': '33163', 'title': 'Wolfgang Amadeus Mozart', 'start_paragraph_id': 2, 'start_character': 143, 'end_paragraph_id': 2, 'end_character': 154, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '33163', 'title': 'Wolfgang Amadeus Mozart', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 752, 'bleu_score': 0.9447680806974831, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14165739679586400938}, 'section': 'Section::::Abstract.'}]}]