440 Hz

440 Hz refers to a specific frequency of sound waves, meaning the wave vibrates 440 times per second. It’s a standard tuning pitch used as a reference for musical instruments, often called "concert pitch." When an instrument produces a note at 440 Hz, it sounds the A above middle C in music. This precise vibration rate creates a clear, consistent tone important for tuning and harmony. The higher the frequency, the higher the pitch we perceive; the lower the frequency, the lower the pitch.