I’ve spent the last week listening to out-of-tune music.

Or maybe I’ve been listening to out-of-tune music all my life without realizing it. Yes, it’s possible. A small cadre of disgruntled listeners insists that we have tuned our instruments incorrectly for decades. And now they want to use digital technology to fix the situation—eliminating all those bad notes with just a click of the mouse.

Musicians don’t agree on much, but they tend to concur that the note A in the middle of the treble staff should be tuned to 440 Hz. The International Standards Organization even issued guidelines to this effect back in the ’50s. But the conspiracy theorists will tell you that this pernicious tuning was promoted by the Nazis—Joseph Goebbels, chief propagandist for the Third Reich, imposed the 440 Hz tuning as part of a heinous plan to warp the consciousness of the masses.

And the record labels may be in cahoots with these Nazis. “The music industry features this imposed frequency that is ‘herding’ populations into greater aggression, psycho social agitation, and emotional distress predisposing people to physical illness,” claims Dr. Leonard Horowitz in his paper “Musical Cult Control.”

Dr. Horowitz is a real doctor—a retired dentist, to be specific. But he gave up fillings and crowns some time ago to promote various conspiracy theories—including his views on tuning instruments. He also suspects the Rockefellers and the Illuminati may have participated in this sinister plot to pollute our songs.

Is it really possible that musicians have been tuning their instruments incorrectly during my entire lifetime? Has my piano tuner (perhaps a member of the Illuminati) been duping me all these years? Is the tuning app on my smartphone a kind of cultural malware designed to destroy music as we know it?

According to true believers, music would generate positive healing energy if A were tuned to 432 Hz. This tuning, they claim, is more aligned with the cosmos and the natural world. “The number 432 is also reflected in ratios of the Sun, Earth, and the moon as well as the precession of the equinoxes, the Great Pyramid of Egypt, Stonehenge, the Sri Yantra among many other sacred sites,” explains author Elina St-Onge. And who do you want to bet on: Stonehenge and the Great Pyramid or Goebbels and the Nazis?

These conspiracy theorists aren’t entirely batty. The tuning of instruments has always been filled with compromises and influenced by competing paradigms. Listeners take for granted the conventional “well tempered” tuning of modern instruments, but this itself was a controversial innovation in its day—it represented a rejection of the Pythagorean heritage and Renaissance thinking on music. But it also made possible the chromatically-rich compositions of Bach and his successors.

The decision to standardize the tuning of A to 440 Hz is a far more recent development. The rich musical traditions of Vienna and Paris were built on a lower tuning than we presently use. In the 19th century, both the French and Austrian government advocated tuning A at 435 Hz, and many other countries followed their lead. And if we can trust a tuning fork used by the manufacturer of Mozart’s pianofortes, his A was way down at 421.6 Hz—almost a G sharp in today’s paradigm. Giuseppe Verdi was an advocate for 432 Hz tuning, and even got the Italian government to pass legislation to this effect (some scholars still call it the Verdi tuning). The Pleyel pianos favored by Chopin came out of the factory with the A tuned to 446 Hz.

The decision to standardize A at 440 Hz gained momentum in the U.S. during the early 20th century. No, you can’t blame Joseph Goebbels for this. Most of the U.S. music industry had switched to 440 Hz by the mid-’20s, and in 1936 the American Standards Association made the change official. A few holdouts refused to budge: the New York Philharmonic and some other orchestras relied on their own preferred tunings—invariably sharper than the standard. And I’ve encountered a few jazz saxophonists who play sharp as well, probably with the misguided intention of adding some bite to their horn lines. But most of the world has come to embrace the Yankee 440.

With the advance of digital technology, listeners can pick their own preferred tuning. During the last week, I have been using a software conversion program called “Return to 432” to shift my music files back to Verdi’s preferred tuning. I’ve listened to a wide range of tracks—rock, jazz, pop, classical—at the lower tuning, and done back-and-forth comparisons.

What did I learn? The difference between the two is modest, but distinguishable. In many instances, I didn’t have a strong preference between the two tunings. But I did slightly prefer the lower tuning for calm, meditative music, and the higher tuning for brash, assertive songs. If I were running a Zen retreat center, I might embrace the alternative tuning. But if I were a DJ playing hot tracks for a dance crowd, I would stick with A at 440 Hz.

I enjoyed listening to Bach at the lower tuning, and felt it also made an improvement in Renaissance polyphony. I got no satisfaction, however, from hearing the Rolling Stones at 432 Hz, and the same was true for Elton John. Bob Marley was a tougher call, and I might be convinced to bring my 432 Hz converter along for a Jamaican vacation. Above all, I distinctly disliked jazz at the lower tuning, whether small combos or big bands. I advise all beboppers and lindy-hoppers to stick with 440 Hz.

After considering these varied responses, I came to the conclusion that music created in the era of 440 Hz is best heard at the current tuning. But when we listen to composers who wrote their music during an era of lower tunings, we should consider recalibrating the music to match the standards of their own time. A jazz or rock band has no reason to change, but a specialist in Baroque music might benefit from a return to a lower scale.

I also played before-and-after tracks for my wife and son in a very unscientific study. They both preferred conventional 440 Hz tuning, although my 15-year-old son—who has a very acute ear, and plays viola, piano, and guitar—was more hesitant about his verdict, and seemed open to considering the advantages of a lower tuning in some instances.

These are hardly conclusive results, but reactions to music are subjective even under ideal test situations. In any event, I’m not ready to join the conspiracy theorists. I will put my week of out-of-tune music behind me, and return without regrets to my old listening habits. But don’t take my word for it, try out the alternative tuning for yourself. Here’s a video comparison of the two tunings you can use to start the process.