Editing C (musical note) (section)

==Frequency==
Historically, [[concert pitch]] has varied. For an instrument in [[equal temperament]] tuned to the [[A440 (pitch standard)|A440 pitch standard]] widely adopted in 1939, middle C has a frequency around 261.63&nbsp;Hz<ref>{{cite web|last=Suits|first=B. H.|title=Physics of Music Notes - Scales: Just vs Equal Temperament|url=https://pages.mtu.edu/~suits/scales.html|website=MTU.edu|publisher=Michigan Technological University|date=1998|access-date=5 February 2024|archive-date=27 November 2023|archive-url=https://web.archive.org/web/20231127155251/https://pages.mtu.edu/~suits/scales.html|url-status=dead}}</ref> (for other notes see [[piano key frequencies]]). [[Scientific pitch]] was originally proposed in 1713 by French physicist [[Joseph Sauveur]] and based on the numerically convenient frequency of 256&nbsp;Hz for middle C, all C's being [[power of two|powers of two]]. After the A440 pitch standard was adopted by musicians, the [[Acoustical Society of America]] published new frequency tables for scientific use. A movement to restore the older A435 standard has used the banners "Verdi tuning", "philosophical pitch" or the easily confused [[scientific pitch]].