A440 (pitch standard)

A440 (pitch standard)
A440 About this sound Play .

A440 is the musical note A above middle C. It has a frequency of 440 Hz and serves as a general tuning standard for musical pitch.

Prior to the standardization on 440 Hz, many countries and organizations followed the Austrian government's 1885 recommendation of 435 Hz. The American music industry reached an informal standard of 440 Hz in 1926, and used it in instrument manufacturing. In 1936 the American Standards Association recommended that the A above middle C be tuned to 440 Hz.[1] This standard was taken up by the International Organization for Standardization in 1955 (reaffirmed by them in 1975) as ISO 16.[2] Although still not universally accepted, since then it has served as the audio frequency reference for the calibration of acoustic equipment and the tuning of pianos, violins, and other musical instruments.

In the period instrument movement, a consensus has arisen around a modern "baroque pitch" for strings (Kammerton) of 415 Hz, baroque for wind instruments and church voices (Chorton) at 466 Hz and "classical pitch" at 430 Hz.[citation needed]

A440 is sometimes referred to as Concert A. (The C above Concert A is called Concert C.)

See also


  1. ^ George Martin (2008). The Opera Companion. Hal Leonard Corporation. ISBN 978-1-57467-168-1. http://books.google.com/books?id=MjTLYqOoi3kC&pg=PA92&dq=440-cps+1936#PPA92,M1. 
  2. ^ ISO 16:1975 Acoustics -- Standard tuning frequency (Standard musical pitch). International Organization for Standardization. 1975. http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=3601. 

External links