Tuning Standards Explained: 432 Hz vs. 440 Hz

by Connor McCoy, iZotope Contributor November 21, 2019
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Have you ever wondered why we tune our instruments to the frequencies that we do? How did we, as a modern society, agree on 440 Hz (A4) as our pitch standard for tuning? Is it based on mathematics or opinion? If you’ve ever had any of these questions, then you’ve already joined the long-standing debate between frequency standards, the most popular of which is the advocacy of 432 Hz over 440 Hz. We’ll leave it up to you to decide whether one sounds better than the other. 

Here, we’ll dive deep into the history of how we chose 440 Hz as the standard for tuning in the modern music world. 

A brief history of tuning standards

Over the past few centuries, the tones that have made up western classical music have fluctuated considerably. Initially, there was no industry-standardized pitch for instruments to tune themselves to, which meant that every orchestra would be tuning to a different pitch than each other. Ever since the 18th century, A4 (the A above middle C) has been the measurement and tuning standard for Western music, but depending on what part of the world the orchestra is from, A4 could range from anywhere between 400 Hz and 480 Hz. 

The unit of “Hz” (pronounced “Hertz”) measures a cycle per second, and is named after Heinrich Hertz, who had successfully proven the existence of electromagnetic waves in 1830. Famous composers like Mozart, Bach, and Beethoven all tuned their orchestras to a different pitch, and even when the tuning fork was invented, the note, when struck, differed depending on whose tuning fork was used. 

After several attempts at remedying the difference in tuning standards between different orchestras (A435, A451, A439), the International Organization for Standardization stood their ground and set an international standardized pitch of 440 Hz for A4 (A440). This isn’t universally accepted among all orchestras. For example, The New York Philharmonic uses 442 Hz, the Boston Symphony Orchestra used 441 Hz, and many symphonies in parts of Europe use 443 Hz or 444 Hz. You can hear how these pitches differ, if only in the slightest sense, here.

Concert hall

What’s the deal with 432 Hz?

Many musicians and non-musicians alike vehemently oppose the industry standard of 440 Hz as a reference for tuning. Just by typing “432 Hz” in any search engine, you’ll find many strong opinions about why A432 is the superior temperament to A440, going so far as to say that A432 contains universal and spiritual healing properties, compared to the “aggravating” and “irritating” properties of A440.

To give a quick background of how 432 Hz came into the picture, we turn to Joseph Sauveur, a French physicist who, in 1713, came up with the concept of a scientific or philosophical pitch. Basically, this system doesn’t follow the A440 tuning reference, it instead places A4 at 430.54 Hz and middle C (C4) at 256 Hz.

He explained that, by placing middle C at 256 Hz, you can create a system where each octave (or factor) of C lands on an even integer, instead of containing dreadful decimals. 

Frequency chart, courtesy of Wikipedia

Giuseppe Verdi, an Italian composer of the 19th century, advocated heavily for the use of this tuning, as does the Schiller Institute.

By using Twelve True Fifths Tuning, a tuning created by author Maria Renold, there’s a way for C256 to fit on the same scale as A432. This website does a much better job of explaining the math than I would ever be able to—if you’re into some slightly nerdier math, it’s an excellent place to start learning about Maria Renold’s 12T5 tuning, or how our A440 equal temperament system works in general.

Lots of websites claim that 432 is a universal number, and by changing our music to represent A432, more natural healing properties occur with the frequencies released by this temperament (despite “Hz” being based on “cycles per second,” and “seconds” being an arbitrary measurement invented by humans). You can’t deny, however, that 432 is an interesting number. It is a sum of four consecutive primes: 103 + 107 + 109 + 113. It is exactly three gross. (A “gross” was a traditional unit of measurement of 144, or 12 squared.) An equilateral triangle whose area and perimeter are equal has a square root of 432. For this reason and many more, multiple people have dedicated themselves to spreading the word about the pros of switching to the 432 Hz system.

If I had to recommend one article to look further into this subject, it would be this one. The author does an amazing job of looking at the argument with an objective and unbiased view, and goes into more depth about the history of 432 Hz and what it claims to offer.

(Adam Neely and Paul Davids both have excellent videos about A = 432 Hz on their respective YouTube channels, if you’re more of a video person.)

Listen for yourself

Okay, enough blabbering—let’s get down to business. You can decide for yourself which tuning sounds better to your ears. Take the test here.

This video also gives a good, unbiased argument for listening to the same piece in different frequencies: 432 Hz vs 440 Hz vs 448 Hz.

I, for one, really enjoy the way that 432 Hz sounds to my ears. When I sing, I find it’s always easier for me to stay in tune with 432Hz. However, I’ve had my friends and family take the test and they preferred the 440 Hz tuning.

I’m unsure about all of the underlying, universal properties circling the subject of 432 Hz, but I can’t deny that it makes me smile when I hear it compared to 440 Hz. For this reason, at the very least, I think it’s worth straying from the A440 system every now and then and discovering your own preferences. But in regards to whether A432 is superior, that’s something you’ll have to choose for yourself.

Learn more audio fundamentals:

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