Is 432 a natural or 'cosmic' frequency?

The hertz is tied to the second, a unit defined by people; a frequency coming out as a whole number in this unit proves nothing. The often-cited Schumann resonances are electromagnetic, not sound.

Can I hear the difference between 432 and 440?

The difference is about 32 cents, a third of a semitone. Played side by side, most people hear it; listening to one alone, most people cannot tell which it is. You can try this blind, with your own ears, in the Tuning experiment.

Was baroque music played at 432?

No. Historically the pitch of A varied over a wide range; today's baroque standard of 415 Hz is not a historical value either, but a compromise.

A history of tuning: from 415 to 443

Before standards

For centuries the pitch of A changed from city to city and from church to opera house; the difference could be more than a semitone. The pitch of an organ, an orchestra or a tuning fork was the habit of that place.

1859: the French normal diapason

In 1859 the French government adopted the 'normal diapason', fixing A at 435 Hz. The physicist Jules Lissajous was among the commission's members; he checked the accuracy of tuning forks with the light figures that bear his name. In 1885 an international meeting in Vienna adopted 435 across Europe.

Verdi and 432

In Italy, after the Milan musicians' congress of 1881, 432 became the Italian diapason; in 1884 432 was also decided for military bands. Verdi favoured a lower pitch and in the 1880s expressed a slight preference for 432. But with the Vienna decision of 1885, 435 spread. Today's 'Verdi tuning' campaign began in the late 1980s.

Where did 440 come from?

440 spread in the early 20th century, especially in the United States; the radio station of the US National Bureau of Standards began broadcasting a 440 Hz reference tone in 1936. In 1939 an international standards meeting in London recommended 440. ISO published it as a recommendation in 1955 and as a standard in 1975 (ISO 16).

The claim that 'the Nazis imposed 440'

This claim is not true. 440 was already common before 1939, and the London meeting was an international standards meeting. The claim appeared in the late 1980s, in writings published by the same circle as the 432 campaign.

Today

The international standard is 440 Hz; many European orchestras play a little higher, around 443. Baroque ensembles mostly use 415 Hz: not a single historical value but a present-day compromise. 432 is not a mainstream standard; Frekans Studio offers it as a tuning preference.

What does the evidence say?

There are small, inconsistent preliminary findings; we offer 432 Hz as a tuning preference.

▲ C · Preliminary/mixed evidence

What do we know?: Small studies reported a borderline drop in heart rate with 432 Hz (33 people) and, in cancer patients with a live monochord, slightly larger drops in heart rate and pulse-wave velocity than with 443 Hz (43 people). In a study of 16 people with high blood pressure, heart rate fell slightly more with 432 Hz music than with 440 Hz; in a pilot with 12 patients with spinal cord injuries, the sleep score improved only in the 432 Hz period. In a trial with 162 students in Türkiye, 432 Hz music raised one salivary biomarker (GRP78), which is not a measure of calm.
What don't we know?: Results are inconsistent, and two studies favour 440 Hz: in kickboxers and in male athletes, 440 Hz music during warm-up was linked to better performance than 432 Hz. In a trial with 42 patients before tooth extraction, both kinds of music reduced anxiety equally compared with no music; the cortisol difference in the abstract comes, in the full text, from the groups' different baseline values (p = 0.99 after adjusting for baseline). In emergency staff, anxiety also fell without music and groups were not compared with each other; in students, attention-test scores did not differ between groups. Studies are small and mostly pilots.

Sources and review note

Evidence levels and sources come from the database; the article adds no new claims. Evidence methodology

Frequently asked questions

Is 432 a natural or 'cosmic' frequency?: The hertz is tied to the second, a unit defined by people; a frequency coming out as a whole number in this unit proves nothing. The often-cited Schumann resonances are electromagnetic, not sound.
Can I hear the difference between 432 and 440?: The difference is about 32 cents, a third of a semitone. Played side by side, most people hear it; listening to one alone, most people cannot tell which it is. You can try this blind, with your own ears, in the Tuning experiment.
Was baroque music played at 432?: No. Historically the pitch of A varied over a wide range; today's baroque standard of 415 Hz is not a historical value either, but a compromise.

Listen and try

Last updated: 6 October 2026 · This article is for information only; it is not medical advice.