About: http://webisa.webdatacommons.org/275135983

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Although still not completely universally accepted, since then it has served as the audio frequency reference for the calibration of pianos, violins, and other musical instruments.
http://www.w3.org/ns/prov#wasQuotedFrom	chicago-piano-tuning.com