A440 (pitch standard)

A440, also known as the pitch standard, refers to the musical pitch of A above middle C, which is set at a frequency of 440 Hz. This means that the note A440 is the sound frequency that vibrates 440 times per second. A440 is commonly used as a tuning reference for musical instruments, ensuring that they are in tune with one another. The concept of A440 has become a standard in the music industry, widely adopted across various genres and styles.