Topic summary
440 Hz
Extracted from the Wikipedia article A440 (pitch standard).
Modern practices
A440 is widely used as concert pitch in the United Kingdom and the United States. In continental Europe the frequency of A4 commonly varies between 440 Hz and 444 Hz. In the period instrument movement, a consensus has arisen around a modern 'baroque pitch' of 415 Hz (with 440 Hz corresponding to A♯) corresponding to Kammerton, another 'baroque' pitch known as Chorton pitch for some organs (in particular, some German church music, e.g. the pre-Leipzig period cantatas of Bach) at 466 Hz (with 440 Hz corresponding to A♭), and a 'classical pitch' at 427–430 Hz.