Question: swan lake the sleeping beauty and the nutcracker are three famous ballets by
[{'answer': 'Pyotr Ilyich Tchaikovsky', 'provenance': [{'wikipedia_id': '2518724', 'title': 'The Sleeping Beauty (ballet)', 'start_paragraph_id': 1, 'start_character': 141, 'end_paragraph_id': 1, 'end_character': 165, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '3784941', 'title': 'Swan Lake (disambiguation)', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['Swan Lake is a ballet by Russian composer Pyotr Ilyich Tchaikovsky. (1875-1876', 'Swan Lake is a ballet by Russian composer Pyotr Ilyich Tchaikovsky. (1875-1876)', 'Pyotr Ilyich Tchaikovsky']}}]}, {'provenance': [{'wikipedia_id': '2518724', 'title': 'The Sleeping Beauty (ballet)', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['The Sleeping Beauty ( / "Spyashaya krasavitsa") is a ballet in a prologue and three acts, first performed in 1890. The music was composed by Pyotr Ilyich Tchaikovsky', 'Pyotr Ilyich Tchaikovsky']}}]}]