432 Hz benefits, chakras and the evidence

What is 432 Hz?

432 Hz is a choice of tuning. It is the pitch given to the note A above middle C, the note an orchestra tunes to before it plays, and every other note is set from it. Nearly all music today puts that A at 440 vibrations a second, the international standard. Put it at 432 instead and every note moves down by the same small step: a song keeps its melody, its chords and its key, and simply sits a little lower.

Musicians measure steps in pitch in cents, where 100 cents make a semitone, the step from one piano key to the next. From 432 to 440 Hz is 31.77 cents: about a third of a semitone, and 1.8 per cent of the frequency. Middle C moves from 261.63 Hz to 256.87 Hz. The French standard of the 1850s, 435 Hz, sits between the two, and its step down to 432 is smaller again, 11.98 cents.

What are the benefits of 432 Hz?

The benefits people describe are about how it feels to listen: a warmer, softer, less strained sound, and for some the sense of music in tune with nature. Those descriptions are what draws most listeners to it. Whether the tuning does anything to the body that 440 Hz does not is a separate question, and eight small trials have tested it by playing the same music at both tunings and measuring what changed.

What each trial compared, and what it found:

• Emergency nurses, 2022, 54 people: a 10-minute break with music at 440 Hz, with music at 432 Hz, or with none. Scores on a questionnaire about tension fell in all three groups. Satisfaction was 9.07 out of 10 with 432 Hz and 8.82 with 440 Hz, not a significant difference.
• Hospital patients, live monochord, 2025, 43 people: a 29-string monochord tuned to 432 or 443 Hz, played on the chest for 15 minutes. Heart rate fell after both, by a median of 3 beats a minute with 432 Hz and 1 with 443 Hz, not a significant difference between them. 24 of the 43 preferred the 432 Hz session, 6 the 443 Hz one.
• Patients before a tooth extraction, 2020, 42 people: 15 minutes of two songs released in 432 and 440 Hz versions, or headphones with no music. Both music groups scored about half as high as the silent group on a questionnaire about dental nerves. Once starting levels were allowed for, 432 and 440 Hz did not differ, on the questionnaire or on cortisol in saliva.
• Healthy volunteers, 2019, 33 people: 20 minutes of the same film soundtracks, tuned to 440 Hz one day and 432 Hz the other. Heart rate averaged 4.79 beats a minute lower with 432 Hz, at the edge of statistical significance. Listeners said they felt more focused and more satisfied.
• Kickboxers, 2025, 28 people: a warm-up to their preferred music at 440 or 432 Hz, then a kicking speed test. Performance was best, and heart rate and perceived effort lowest, after the 440 Hz warm-up.
• Male athletes, 2025, 22 people: a warm-up to their preferred music at 440 or 432 Hz, then sprint and jump tests. Music at either tuning beat warming up without it, and the authors found the gains more noticeable at 440 Hz. Heart rate did not differ.
• Adults, 2018, 16 people: music switching between 440 and 432 Hz every 10 minutes, after a mental arithmetic task. Heart rate fell a little further during the 432 Hz music: 7.2 against 5.3 beats a minute.
• Spinal unit patients, 2020, 12 people: their own favourite music, 30 minutes a day, at 432 Hz for one period and 440 Hz for another. Sleep scores rose after the 432 Hz period and not after the 440 Hz one, but the two were never compared directly, and listening times varied.

Taken together, the trials are small and point different ways. The differences in favour of 432 Hz are a few beats a minute of heart rate, each at the edge of statistical significance. Where satisfaction and questionnaire scores were compared directly between the two tunings, they did not differ, and both sports trials found 440 Hz better. The 432 Hz versions were made in at least five different ways, from pitch-shifting software to commercial recordings of different lengths to a live instrument, and three of the trials share a co-author, an independent musician. No systematic review of 432 Hz has been published.

Other studies played 432 Hz music against silence, white noise or binaural beats, mostly to people waiting for dental work. Some found lower heart rates in the people given music than in those given none, some found no difference, and one found a stress marker in saliva higher after 432 Hz music than after silence. With no 440 Hz group, none of them can say whether the tuning mattered: they test music, not 432 Hz.

For listening, that leaves taste. There is no good evidence that 432 Hz does something 440 Hz does not, and nothing against choosing it because it sounds warmer to you. The 432 Hz page plays the tone free, the last section of this guide shows how to compare the two tunings for yourself, and the guide to the science of sound healing looks at the wider research on listening.

Does 432 Hz sound different?

It sounds lower, and only a little. Side by side, most attentive listeners can hear the step. A review of how we hear puts the finest difference people can tell between two tones at about 0.2 per cent, where hearing is sharpest, and in one study even people with no musical training reliably caught pitch changes of 0.8 per cent. 432 and 440 Hz are 1.8 per cent apart.

Heard on its own, with nothing to compare it with, the step mostly disappears. Absolute pitch, the ability to name a note without a reference, is estimated to occur in fewer than one person in 10,000 in the United States and Europe. Without it, listeners still carry a faint memory of standard tuning: in a University of Chicago study, people sorted single piano and violin notes into in tune and 50 cents sharp correctly 55.8 per cent of the time, a little better than the 50 per cent of guessing. And when the same team played the first movement of Brahms's First Symphony to people with absolute pitch, lowering its tuning by two cents a minute, it ended 33 cents flat and none of them noticed. That is almost exactly the distance from 440 down to 432.

Played at the same moment, the two tunings clash. Two tones 8 Hz apart drift in and out of step eight times a second, so the sound swells and fades at that rate: the beat that musicians listen for when they tune. That is why an orchestra, or two people playing together, must agree on one A.

Does either sound better? The acoustician Trevor Cox ran a web experiment in which ten pieces of music were each shifted to seven tunings, from 416 to 465 Hz, and visitors picked the better of two clips, 1,396 times in all. Moving the music lower made no difference to which they preferred, and 432 and 440 Hz were rated with equal preference; only the higher tunings were liked less, which Cox put down to the pitch-shifting software. It was a blog experiment, not a peer-reviewed study. In the 2019 trial above, listeners said they felt more focused and more satisfied after the 432 Hz session. Taste, in other words, varies.

Why is 440 Hz the standard?

Because an international conference agreed it in London in 1939, when much of the world was already close to it. For centuries before that, the A wandered. A 1938 account in Nature, drawing on Alexander Ellis's history of musical pitch, puts it anywhere from 374 to 567 Hz between the fourteenth and seventeenth centuries, and from about 424 to 494 Hz in the nineteenth, rising through "a striving for increased brilliancy". Ellis measured some of the old forks himself. The fork Handel left at London's Foundling Hospital, when Messiah was performed there in 1751, gave an A of 422.5 Hz, and a fork from the Viennese instrument maker Stein, the pitch to which Mozart's clavichords and pianos were tuned, 421.6 Hz: lower than 432, and lower still than 440.

Standards came one country at a time. A conference of physicists in Stuttgart adopted 440 Hz in 1834. France fixed its "diapason normal" at 435 Hz in 1859, and a conference in Vienna endorsed it in 1885. Britain stayed higher: London's Philharmonic pitch went from 433 Hz in 1826 to 455 Hz, and British Army bands came down from 455 to 439 Hz only in 1927. In the United States, the American Federation of Musicians adopted 440 Hz in 1918 and the American Standards Association in 1936.

Radio settled it. Broadcasters were exchanging concerts across borders, and radio measurements made in Germany found European broadcasts averaging about 443 Hz. In May 1939 an international conference met at the BBC's Broadcasting House in London, organised by the British Standards Institution for the International Standards Association, with delegates from France, Germany, Britain, the Netherlands and Italy. The standards bodies of France, Germany, Britain and the United States had each proposed 440 Hz, the Dutch and the Swiss agreed, and, as the conference's president reported in Nature, it unanimously recommended 440 Hz. The International Organization for Standardization took it up after the war, in a recommendation of 1955 and then ISO 16, which says the A "shall be 440 Hz" and was last confirmed in 2022.

The numbers behind the chart

Year	Who set it, or what was measured	A, in Hz
1751	Handel's tuning fork, London	422.5
1780	Stein's fork, Vienna: the pitch of Mozart's pianos	421.6
1826	London Philharmonic pitch	433
1834	Stuttgart conference of physicists	440
1845	London Philharmonic pitch, raised	455
1859	French diapason normal, by law	435
1881	Milan congress of Italian musicians, a recommendation	432
1884	Italian army bands, by order of the War Ministry	432
1885	Vienna conference, unanimous	435
1887	Italian royal decree	435
1896	Philharmonic Society, London	439
1899	British piano makers	439
1918	American Federation of Musicians	440
1925	Music Industries Chamber of Commerce, United States	440
1927	British Army bands, lowered from 455	439
1936	American Standards Association	440
1938	European concert broadcasts, average	443
1939	London conference, unanimous	440
1955	ISO Recommendation R 16	440
1975	ISO 16	440

Did Verdi want 432 Hz?

Not at first. Verdi wanted Italy to share one pitch with the rest of Europe, and the pitch he asked for was the French one, 435 Hz. When an Italian commission settled on 432 Hz instead, he accepted it, because the difference was, in his words, almost imperceptible.

The number came from Milan. In June 1881 a congress of Italian musicians met there to give the country one pitch. Its organisers proposed the French standard, but the congress voted unanimously for a "rational" A of 864 simple vibrations a second, a count of every swing back and forth, which is 432 Hz. In 1884 the War Ministry ordered the army's bands to tune to it, and by the spring of 1885 the Gazzetta Musicale di Milano counted only two or three of the army's 96 bands still to change; the Milan Conservatory had adopted it too.

Verdi's view is in a letter from Genoa, dated February 1884, which the Gazzetta Musicale di Milano printed that year. In translation:

Ever since the normal diapason was adopted in France, I advised that we follow the example, and I formally asked the orchestras of several Italian cities, La Scala's among them, to lower their pitch to the French normal. If the music commission set up by our Government believes, for mathematical reasons, that it should reduce the 870 vibrations of the French fork to 864, the difference is so small, almost imperceptible to the ear, that I very willingly agree.

870 and 864 are those simple vibrations, so the step he accepted was from 435 to 432 Hz. Verdi also wrote that lowering the pitch takes nothing from the sonority and brio of a performance, and gives it instead "something nobler, fuller and more majestic" than the shrieks of a pitch set too high. In the same letter he called Rome's proposal of 900, which is 450 Hz, a grave, a very grave error, and asked for one pitch for the whole musical world: "Musical language is universal: why then should the note called A in Paris or Milan become a B flat in Rome?"

He got one pitch, though not 432. In November 1885 an international conference in Vienna, where the physicist Pietro Blaserna and the composer Arrigo Boito represented Italy, proclaimed the French A of 435 Hz unanimously. Italy's government had told its delegates to accept, even if it was not 432, whichever pitch could gather a large majority, and they did. In October 1887 a royal decree made 435 Hz the standard across Italy. So 432 Hz was Italy's pitch only by a minister's order for the army bands and by the choice of a few institutions, such as the Milan Conservatory; the national standard, by royal decree, was 435 Hz.

Was 440 Hz chosen by the Nazis?

No. The story goes that Joseph Goebbels's Radio Berlin organised the 1939 conference to impose a German pitch on the world. In the conference's own record, described above, the British Standards Institution organised it and the BBC hosted it, and the French, American and British standards bodies had proposed 440 Hz just as the German one had. In the United States, 440 Hz had been the musicians' union's pitch since 1918, and in 1885 Blaserna was already calling 440 Hz "the so-called German" pitch, long before the Nazis.

The Goebbels story appears, in the earliest version that can be dated, in an article of September 1988 in Executive Intelligence Review, a magazine of Lyndon LaRouche's political movement, quoting a French advocate of 432 Hz writing in 1950. That April the movement's Schiller Institute had opened a campaign for 432 Hz in Milan, claiming that Verdi had established it by decree, and that summer Italian senators put forward a bill to make 432 Hz the law. The Senate's committee changed the figure to 440 Hz, with the bill's first signatory agreeing, and in May 1989 it became the law that fixes Italy's A at 440 Hz.

So the two stories most often told about 432 Hz, that Verdi decreed it and that the Nazis replaced it, were both spread by the same campaign in 1988, and the records of the 1880s and of 1939 bear out neither.

Why 432? Where the number's other claims come from

Much of the appeal is the number itself. 432 is 2 × 2 × 2 × 2 × 3 × 3 × 3, so it divides neatly in many ways, and it is the A that belongs to a C of 256 Hz in tuning by pure fifths. That C is the so-called scientific pitch, and it goes back to the acoustician Joseph Sauveur: in 1713 the French Academy of Sciences reported that he had made it his fixed reference, rather than the 244 vibrations a second he reckoned for the middle C of a harpsichord, because 256 is a power of two, so its octaves fall on 1, 2, 4 and so on. Stack three fifths on it, each a ratio of 3 to 2, and you reach an A of 864 Hz, exactly an octave above 432.

The result depends on the tuning. Pure fifths are not how a modern piano is tuned: in its equal steps the A above C = 256 comes out at 430.54 Hz, and in just intonation, where the major sixth is a ratio of 5 to 3, at 426.67 Hz. So "C = 256" and "A = 432" are the same proposal only in Pythagorean tuning.

A second route reaches 432 by astronomy. Hans Cousto's planetary tuning tables raise the length of the Earth's year by 32 octaves to a tone of 136.10 Hz, a C sharp, and give the A that belongs with it as 432.10 Hz, about 31 cents below 440. That is the reasoning behind the Earth year tone, 136.10 Hz, and the guide to planetary frequencies explains his method.

Both routes count in hertz, vibrations per second, and the second is a unit people chose: first a fraction of the day, today a fixed number of vibrations of the caesium atom. In any other unit of time the same pitch carries a different number, so the neatness of 432 belongs to the second, not to the sound.

The objection is not new. In 1885 Blaserna, back from Vienna, set out for Italy's academy of sciences, the Accademia dei Lincei, why the case made for 432 Hz, that it gives the notes of the scale whole numbers because "nature knows no fractions of vibrations", was "completely wrong".

Another claim says 432 matches the Earth's own resonance of 8 Hz, since 432 is 54 × 8. The Schumann resonances, the ringing of the gap between the ground and the ionosphere that lightning sets off, have their lowest peak near 7.8 Hz, and a physics paper on the resonances notes that the peaks shift between day and night. Nothing in the physics ties them to a musical A.

Which chakra is 432 Hz?

None, in the texts the chakra system comes from. The best-known of them, the Sanskrit Ṣaṭ-cakra-nirūpaṇa, which Arthur Avalon translated as The Serpent Power, describes each chakra by its petals, the letters written on them, a colour, an element and a seed syllable, from Lam at the root to Om between the eyebrows. It gives no pitches. The only musical notes in the book are the seven notes of the Indian scale, which Avalon's introduction places together in the throat lotus: all seven in one chakra, not one to each.

The colours most people know, one for each chakra in rainbow order, are a twentieth century Western addition. As a history of the Western chakra system in the Theosophical Society's journal puts it, in the older sources:

the chakras have colors, but there is no rainbow; they have qualities and spiritual powers, but not those on this list.

Musical scales came by the same modern Western route: the Society's own reading list on chakras includes books from 1977 and 1992 that pair the chakras with the notes of a scale. So there is no traditional answer to which chakra 432 Hz belongs to. Any chart that gives one is a modern correspondence, like the rainbow colours, and you are free to use it as a focus for attention or to leave it. The guide to chakras and frequencies explores those maps further.

How can you hear the difference for yourself?

Start with the tone on its own. The player at the top of this guide plays 432 Hz here, and the 432 Hz page plays the full version free, as a pure tone or with strings tuned to its octaves. Listen at a low volume for a few minutes and notice how it sits with you. The page for when you need to unwind offers it as a soft backdrop for reading or a slow evening at home.

Then compare the two tunings on the same music. Most tuner apps, and many digital pianos and keyboards, let you set the reference A to 432 or 440 Hz. Ask someone to play a short piece both ways, in an order you do not know, and see whether you can tell which is which, and whether you prefer one. Then sound both As together and listen for the slow swell of the beat, eight times a second.

Sources and limits

The trials that compared 432 with 440 Hz are small, from 12 to 54 people each, and used different music and different ways of making the 432 Hz version, so their results cannot simply be added together, and no systematic review of 432 Hz exists. The history rests on the records themselves, read in scans of the original papers, journals and laws; translations from Italian and French are Harmonance's own. Pitches before 1939 were set and measured at different temperatures, so the chart's values are approximate.

1. Calamassi and colleagues, music at 440 against 432 Hz for emergency nurses, 2022: the 54 nurses, their tension scores and their satisfaction.
2. Hohneck and colleagues, sound sessions tuned to 432 or 443 Hz, 2025: the monochord trial's heart rates and preferences.
3. Aravena and colleagues, music at 432 and 440 Hz before a tooth extraction, 2020: the questionnaire scores and cortisol in saliva.
4. Calamassi and Pomponi, music tuned to 440 against 432 Hz, 2019: the 33 volunteers' heart rates and what they reported.
5. Jebabli and colleagues, 440 against 432 Hz music in kickboxers' warm-ups, 2025: kicking speed, heart rate and perceived effort.
6. Jebabli and colleagues, preferred music at two tunings in athletes' warm-ups, 2025: sprint and jump results and heart rate.
7. Halbert and colleagues, low frequency music and heart rate, Music and Medicine, 2018: the 16 adults' heart rates at the two tunings.
8. Calamassi and colleagues, music at 432 and 440 Hz on a spinal unit, 2020: the sleep scores and the study's own limits.
9. Di Nasso and colleagues, 432 Hz music during root canal work, 2016: music against no music, with no 440 Hz group.
10. Mousavi and colleagues, music for endodontic patients, 2025: no difference from the control group.
11. Bozok and colleagues, music at 432 and 528 Hz and saliva markers, 2026: the stress marker that rose after 432 Hz music.
12. Andrew Oxenham, How we hear, 2018: the finest difference in pitch people can tell.
13. Tervaniemi and colleagues, pitch discrimination in musicians and non-musicians, 2005: changes of 0.8 per cent heard without musical training.
14. Deutsch and colleagues, absolute pitch among conservatory students, 2006: how rare absolute pitch is.
15. Van Hedger and colleagues, telling in-tune from out-of-tune, 2017: single notes judged correctly 55.8 per cent of the time.
16. University of Chicago, perfect pitch may not be absolute after all, 2013: the Brahms symphony lowered 33 cents without anyone noticing.
17. Trevor Cox, pitch shifting to 432 Hz does not improve music, 2013: the web experiment and its 1,396 choices.
18. Alexander Ellis, On the history of musical pitch, Journal of the Society of Arts, 1880: the old forks Ellis measured himself, Handel's of 1751 and Stein's from Vienna.
19. G. W. C. Kaye, International standard of musical pitch, Nature, 1938: the wandering of the A before 1939 and the national standards from 1826 to 1936.
20. G. W. C. Kaye, International standard of concert pitch, Nature, 1939: the London conference: who organised it, who came, what each country proposed, and the vote.
21. ISO 16:1975, preview: that ISO 16 replaced the 1955 recommendation, R 16.
22. International Organization for Standardization, ISO 16:1975, archived page: 440 Hz, last confirmed in 2022.
23. Pietro Blaserna, the Vienna conference and a uniform pitch, Nuova Antologia, 1886: that the Milan congress's organisers proposed the French pitch.
24. Gazzetta Musicale di Milano, proceedings of the congress of Italian musicians, 1881: the unanimous vote for 864 simple vibrations.
25. Giornale Militare Ufficiale, act 153, 1884: the army bands' A of 432 complete vibrations.
26. Gazzetta Musicale di Milano, the normal pitch, 1885: the army bands still to change and the Milan Conservatory.
27. Gazzetta Musicale di Milano, Verdi's letter, 1884: Verdi's own words on 870, 864 and 900.
28. Pietro Blaserna, on the Vienna conference, Rendiconti della Reale Accademia dei Lincei, 1885: the delegates' instructions, the unanimous vote for 435 Hz, the "so-called German" 440, and why the case for 432 was wrong.
29. Gazzetta Ufficiale del Regno d'Italia, royal decree 5095, 1887: 435 Hz as Italy's standard.
30. Laurent Rosenfeld, How the Nazis ruined musical tuning, Executive Intelligence Review, 1988, archived copy: the earliest dated version of the Goebbels story.
31. Executive Intelligence Review, Schiller Institute begins revolution in musical tuning, 1988, archived copy: the Milan campaign and its claim about Verdi.
32. Senato della Repubblica, bill 1218, 1988: the proposal to make 432 Hz the law.
33. Senato della Repubblica, 7th Committee, record of its sitting in February 1989: the change to 440 Hz and the first signatory's agreement.
34. Law 170 of 1989, Normattiva: Italy's A of 440 Hz at 20 degrees.
35. Histoire de l'Académie royale des sciences, 1713: Sauveur's fixed pitch of 256 and why he chose it.
36. Hans Cousto, tuning data for the planets: the Earth year tone and its A of 432.10 Hz.
37. BIPM, the second: how the second is defined.
38. Z. K. Silagadze, Schumann resonance transients, arXiv: the resonances' peaks and their shift between day and night.
39. Arthur Avalon, The Serpent Power, Digital Library of India copy: how the Sanskrit text describes each chakra.
40. Arthur Avalon, The Serpent Power, introduction: the seven notes placed together in the throat lotus.
41. Kurt Leland, The rainbow body, Quest: the rainbow colours as a modern Western addition.
42. Theosophical Society, Olcott Library reading list on chakras: the books of 1977 and 1992 that pair the chakras with scales.