If you scroll through social media for long enough, you'll probably find videos claiming that listening to songs tuned to "A ...

A440, also known as Stuttgart pitch, is the musical pitch corresponding to an audio frequency of 440 Hz. This pitch standard is crucial for tuning musical instruments, particularly the note A above ...

For at least 80 years, that standard pitch frequency has been A440 Hz — which defines the A note above middle C, and by extension, all the other notes around it. But this longstanding tuning standard ...