The Chrome Extension That’s Rekindling the 432 Hz Music Conspiracy

In the dusty corners of TikTok, Reddit, and YouTube’s comment sections, one peculiar conspiracy refuses to die. It has to do with the way music is tuned—specifically, the frequency of the note A above middle C. Much of Western music is tuned to 440 Hz. But according to a passionate group of musicians, spiritualists, and conspiracy theorists, we’ve all been misled.

They say the correct frequency that our instruments should be tuned to is 432 Hz—and there’s a Chrome extension that makes it easy to see for yourself, one track at a time. MusicRetuner.com—which lets anyone instantly retune their favorite songs from 440 Hz to 432 Hz while streaming music on YouTube or Apple Music—has reignited the 432 Hz debate online, with everyone from music enthusiasts, sound engineers, and orchestra musicians weighing in.

Why is this such a heated debate, and why should we care to listen—literally?

1. What’s a Hz?
2. So What’s The Deal With 432 Hz?
3. The Conspiracy (and a Not-So-Brief History of Pitch)
4. 440 Hz vs. 432 Hz: What’s The Difference?
5. Why Is This Extension Causing a Stir?
6. Scientists vs. Spiritualists
7. Final Note

What’s a Hz?

Before we get into the argument, let’s first understand: What is a Hz?

Hz is the abbreviation for hertz, a unit that measures frequency (how many times a wave repeats per second). It’s named after Heinrich Rudolf Hertz (1857–1894), the first person to provide conclusive evidence of the existence of electromagnetic waves.

In music, when a person tunes instruments, the process begins with using a root or anchor frequency around which the entire scale is then assigned. So, for example, the lowest key on a piano, when tuned to A4 = 440 Hz, is the A0—meaning the A note in the 0 octave, which equals 27.5 Hz. The highest key on a piano is C8, meaning the C note in the 8 octave which rounds to 4186 Hz.

So What’s The Deal With 432 Hz?

According to believers, 432 Hz isn’t just any frequency—it’s the frequency. They call it “harmonically resonant” and “more aligned with nature”; they say it helps “[connect] us to the frequency of the cosmos.” Some claim it reduces anxiety, improves sleep, decreases heart rate, balances chakras, enhances creativity, and opens your pineal gland.

While many theories for the significance of 432 Hz exist, the main one claims that 432 Hz corresponds to mathematical patterns found in the universe—like the golden ratio, planetary orbits, and ancient architecture. There are also anecdotal claims (though no hard evidence) that instruments in ancient Egypt, Greece, and India were tuned to this pitch; that it has been mentioned in the Bible; and that monks use this frequency in their chants.

Search “432 Hz vs 440 Hz” on YouTube and you’ll find countless side-by-side comparisons. One version sounds “warmer,” “more organic,” or “emotionally deeper.” The other? “Cold.” “Sharp.” Or simply “wrong.”

Music is a form of art that is meant to make us feel, remember, and often forget. And from the thousands of comments found across the web, many people claim that 432 Hz simply does this better.

The Conspiracy (and a Not-So-Brief History of Pitch)

Now things get weird.

The conspiracy hinges on the idea that 440 Hz was intentionally promoted to dull our consciousness. One supposed origin story involves Nazi Germany. The story goes that in the late 1930s, Joseph Goebbels, Hitler’s minister of propaganda, pushed for a 440 Hz standard. His goal was to use music’s subtle psychological influence for mass control.

It’s a juicy theory, but historians have cast doubt on the Nazi connection.

Contrary to claims that 432 Hz was the standard for thousands of years, pitch was traditionally highly variable. In the 19th century, Alexander J. Ellis examined the pitches of various instruments over the preceding centuries and found the A above middle C could range from 373.7 Hz for a 17th-century French foot pipe to 567.3 Hz for an old German church organ. But in an era when music was made and consumed locally, such variation didn’t particularly matter.

As technology improved (like with the invention of the tuning fork) and music started to travel widely, these variations started to become problematic. Already in the early 18th century Bach had difficulties reusing a cantata in Leipzig that he had composed in Weimar because of pitch problems.

Another problem emerged in the 19th century. As the orchestra became its own thing and started to appear in larger halls, people preferred the more brilliant sounds of a higher pitch, so musicians started tuning higher. Then other musicians tuned higher than the first group, and so on—a trend that is often referred to as “pitch inflation” [PDF].

But this arms race had a drawback for singers, who found themselves struggling to hit ever higher and higher notes—so things started to become standardized. There was an early attempt among German physicists in 1834 to standardize A at around 440 Hz, but according to musicologist Bruce Haynes’s A History of Performing Pitch: The Story of ‘A,’ this “seems to have had no apparent effect on performance pitch whatsoever.”

The more important effort was when France set A to be 435 Hz (not 432) in 1859. Known as the diapason normal, this started to become a European standard that was even (obliquely) worth a mention in the Treaty of Versailles that ended World War I. (Though it’s often said on the internet that the Treaty of Versailles mandated a 440 Hz pitch, that’s incorrect: Article 282 mentions the “Convention of November 16 and 19, 1885, regarding the establishment of a concert pitch.” And that conference—not so much a convention—chose 435.)

But not everyone was on board. The United Kingdom especially had issues converting to this lower pitch. Richard Wagner was recorded as complaining “bitterly of the inconvenience his singers had been put to on account of the fact that the pitch they were obliged to sing [in the UK], was so much higher than that which they were accustomed to.”

In 1896, the UK’s Royal Philharmonic Society switched to a new tuning, 439 Hz, at least ostensibly (and probably incorrectly) because they felt the diapason normal was taken at a colder temperature than British orchestra halls. Pitch inflation was also still taking place, so even much of the continent was above the “official” 435 Hz and reaching the 440 range. In America, the pitch had also reached 440 Hz, and by the mid-1930s, that was officially the standard pitch in the country. 

Come the 20th century and the advent of broadcasting, the question of pitch standardization became more of a necessity, and the International Broadcasting Union urged a meeting of the International Standards Association. In 1939, then, a meeting of several nations was held, and according to a BBC engineering book from the 1970s, “Agreement had almost been reached that the standard should be 439 Hz when it was suggested that it might be easier to generate a tuning note at 440 Hz than at 439 Hz by electronic means (439 being a prime number).” It was noted at the time that 440 Hz was the American standard pitch, not the German, though 440 Hz was closer to what was actually being used in most countries.

That year, a newspaper gave more reason to doubt the 440 = Nazi story, wondering “if Nazi Germany was represented at that meeting, since early last spring Nazi officials decreed by state orders that the pitch for all wind instruments in Germany should be ‘A-435.’ ” But Germany had indeed been present.

Then World War II started, and nobody really cared about international pitch standards. Following the war, in the 1950s, 440 Hz was again recommended, and became an official standard in 1975. Even today, pitch inflation hasn’t been kept totally at bay, and several orchestras are reported to tune slightly above 440.

So while the timing (around WWII), Germany's involvement (and because 440 Hz is sometimes referred to as the Stuttgart or German pitch due the 1834 effort, despite that pitch not being historically popular in the country), and the supposed musical dissonance (some say 440 Hz literally “feels” worse) have kept the conspiracy alive for decades, the true history is far more complex.

440 Hz vs. 432 Hz: What’s The Difference?

Why Is This Extension Causing a Stir?

Until recently, if you wanted to hear digital music tuned to 432 Hz, you had two choices: You could manually convert songs you owned, one song at a time, or search YouTube and Spotify for pre-recorded music that claimed to be tuned to 432 Hz.

Neither option is perfect. Any attempt to use a popular music software like Ableton or Protools would require investing a significant amount of time to learn how to operate it, and then more time to convert each song. Not exactly a plug-and-play solution. Most people have used free music converter websites, but those tend to be super slow and end up creating a lot of clutter on their hard drives.

As for the second option: Since both YouTube and Spotify host content that practically anyone can upload, many independent artists have taken advantage of the trend, labeling long tracks as 432 Hz even though it’s impossible to verify that the music tracks they uploaded were actually tuned to 432 Hz. Plus, nearly all of the 432 Hz music you’ll find on YouTube and Spotify are meditation or elevator tracks.

Music Re-Tuner, however, works directly in your browser, intercepting the output of any YouTube or Apple Music stream in real time—freeing you from having to download files, edit them, or use weird third-party converters. Users willing to pay the monthly fee have found their minds blown: One post on Reddit, in which a user wrote that they “Just used a tool that turns YouTube Music into 432 Hz … my favorite track made me cry. Is this real??” got hundreds of upvotes and comments. Another TikTok video racked up thousands of views comparing Johnny Cash’s cover of “Hurt” at 440 Hz vs. 432 Hz, demonstrating how profound the change could be.

Posts like these inspired more people to get the extension to check the difference for themselves rather than relying on others to show and tell. That caused more comments depicting emotional responses to music retuned to 432 Hz, in turn inspiring more people to use the extension. All of a sudden, the 432 Hz theory wasn't just something to read about—it was something people could hear and feel, in real time, with their favorite music, without needing a DAW (digital audio workstation) or a doctorate in audio engineering to just try it out.

Scientists vs. Spiritualists

Naturally, not everyone’s on board with this interpretation of the effects of 432 Hz.

According to music producer Assaf Dar Sagol, “432 Hz seems to be just another number without any special significance over others. Tuning your music to a specific frequency will not unlock cosmic powers, or make your music sound better or worse.”

Trevor Cox, a professor of acoustics engineering at the University of Salford in the UK, ran a web experiment to test the theory. “People may think that music sounds better at 432 Hz and therefore applying a pitch shifter to their favourite tunes will improve quality,” he wrote, “but for people who took part in my experiment this wasn’t true.”

Still, believers argue that science isn’t always the best lens. For them, 432 Hz isn’t just a pitch—it’s a feeling. A sensation. A moment of sonic alignment in a chaotic world.

As one TikTok comment put it: “I don’t care if it’s placebo. It makes me feel better. That’s enough.” Others—from professional musicians to music engineers—share the profound effect they’ve felt in every performance that shifted away from 440 Hz, stating that the entire audience was in a joint frequency that felt harmonious and real.

Final Note

Whether you think 432 Hz is the secret to spiritual awakening or just a slightly flatter A, one thing’s clear: The internet loves a good musical mystery.

At the very least, re-tuning to 432 Hz gives you a fun way to re-listen to your favorite songs. Maybe you’ll find depth and re-experience music in ways you didn’t know you could. And maybe—just maybe—you’ll hear something you didn’t before.