A4sävelen

A4sävelen is a term used in music theory and practice that refers to the musical note A with a frequency of 440 Hertz. This specific pitch is internationally recognized as the standard tuning pitch for orchestras and other musical ensembles. The A4 note is typically produced by a tuning fork or a piano's A4 key, and other instruments are then tuned to match this reference.

The adoption of A4=440 Hz as the standard tuning pitch occurred over time, with various historical standards existing. While some regions and orchestras historically used slightly higher or lower pitches, the 440 Hz standard gained widespread acceptance throughout the 20th century. This standardization facilitates ensemble playing, allowing musicians to perform together accurately regardless of their instrument.

The frequency of 440 Hz for A4 is not an inherent physical property of music but a convention. Its precise origin and the reasons for its widespread adoption are debated among musicologists, but its role in modern musical practice is undeniable. In digital audio and music software, A4 is often used as a reference point for pitch correction and audio analysis.