Question: what are the 3 foot pedals on a piano
[{'answer': 'the sostenuto pedal', 'provenance': [{'wikipedia_id': '8306275', 'title': 'Piano pedals', 'start_paragraph_id': 1, 'start_character': 205, 'end_paragraph_id': 1, 'end_character': 224, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'the sustaining pedal ( or damper pedal )'}, {'answer': 'the soft pedal ( or una corda )'}, {'provenance': [{'wikipedia_id': '8306275', 'title': 'Piano pedals', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 408, 'bleu_score': 0.972407137066537, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3587340527259552113}, 'section': 'Section::::Abstract.'}]}]