A440 - What does standard tuning mean?

By Mark Wade, of Melismatics, Teacher and Assistant Director of Music Education at Twin Town Guitars

When you hear something that is “in tune,” what does that really mean? To most people, it means that what they’re hearing is in tune with itself. Meaning, if an instrument is tuned consistently flat or sharp, it will still sound in tune when heard by itself. Only people with a discerning ear or perfect pitch will notice if the entire instrument is out of tune with standard tuning.

Standard tuning is A - 440 Hz, which means that the A above middle C on a keyboard will vibrate 440 times per second.

But how did that become the standard? For centuries, tuning was ambiguous and varied from region to region. Primarily, cities would tune to the largest instrument—the organ—and well, every organ was made differently. The tuning could vary as wildly as a third above or below what is now standard. Traveling vocal soloists would struggle immensely with the varied tunings from region to region.

Eventually, tuning forks were invented but they also lacked a standard. But in 1834, Johann Heinrich Scheibler invented a tonometer that contained 56 differently pitched tuning forks. He then traveled to different countries to analyze which pitches the forks were tuning to and offered A - 440 Hz as a compromise and standard. The United States adopted A – 440 Hz in 1910 and many countries followed in 1939. In 1955 A - 440 Hz was adopted by the International Organization for Standardization.

Despite it being standard, there are still a number of orchestras that tune to different frequencies. For example, the New York Philharmonic uses 442 Hz. Most electronic tuners will give you the option to set the Hertz. So if you tune your guitar, but it doesn’t sound in tune with others, make sure your Hertz is set to 440!