About: http://webisa.webdatacommons.org/382961137

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	In the 1950s, the International Organization for Standardization adopted A440 as the standard frequency for the note A above middle C, on pianos and other musical instruments.
http://www.w3.org/ns/prov#wasQuotedFrom	wisegeek.com