For parents, teachers and anyone who gets asked
What 432 Hz and 528 Hz are really about
Your child is learning an instrument, and somewhere you came across the number 432 — in a video, in an app, in a conversation after the lesson. Here is what is musically true about it, what isn’t, and what it means for lessons.
Concert pitch is an agreement, not a constant of nature. That it can be something other than 440 Hz is historically correct.
There is a real, small history behind 432 Hz — and a great many claims that do not hold up.
For lessons the question is practical, not philosophical. Listening: harmless. Retuning: a decision with consequences.
Concert pitch is an agreement
When an orchestra tunes, it agrees on a single note: the a′, the reference pitch. Everything else follows from it. Since 1955 that has been standardised at 440 Hz.
This standard is younger and looser than most people think. Before 1859 there was none at all — surviving organs and tuning forks show an a′ between roughly 390 and 505 Hz. And even today many orchestras do not keep to it: Germany and Austria usually sit at 442 to 443 Hz, the Vienna Philharmonic since the 1980s at around 444.
A semitone is 100 cents. Between 432 and Vienna’s 444 lies almost half a semitone — considerably more than the gap the debate is usually about (432 against 440: 31.8 cents). A child in Vienna does not grow up with exactly 440 anyway.
Where the number 432 comes from
The historical core is genuine, but small. A congress of Italian musicians in Milan recommended 432 in 1881, and an Italian military decree of 1884 prescribed it for military bands. As early as 1885 an international conference — in Vienna, of all places — settled on 435, and with that the episode was effectively over.
Verdi is often called as the star witness. He did argue for a lower pitch, but his preference was the French 435; he accepted 432 with the remark that the difference was “so small, almost imperceptible to the ear”. The term “Verdi tuning” for 432 was only coined in 1988, a good eighty years after his death, as part of a political campaign.
What you actually hear
The difference between 432 and 440 is 31.8 cents, just under a third of a semitone. In direct comparison — the same piece, once each way — that is clearly audible; the discrimination threshold lies at a few cents.
Without a comparison practically nobody can identify it. Absolute pitch is rare, and even those who have it hear a pitch, not a number. Music tuned lower can subjectively feel warmer or calmer — because it is lower, not because 432 is a special number. At 431 or 433 the impression would be the same.
528 Hz and the “Solfeggio frequencies”
These numbers often come up in the same breath as 432, although they have an entirely different origin — and do not even fit together with 432.
The list of six “Solfeggio frequencies” (396, 417, 528, 639, 741, 852) first appears in a book from 1999. Its author states that he received them in a vision, derived from the verse numbers of the Book of Numbers. With the medieval solfeggio of Guido of Arezzo they share nothing but the syllable names.
And arithmetically: 528 Hz is the c″ — but only if the a′ sits at around 444 Hz. At a reference pitch of 432 the c″ lies at 513.7 Hz. So anyone listening “in 432 Hz” is precisely not listening to 528. The two numbers rule each other out.
What is often claimed — and what can be checked
People used to tune lower than today
trueBut not uniformly, and not at 432. The documented values scatter between roughly 390 and 505 Hz, depending on place, century and instrument.
Mozart, Hendrix or Bob Marley played in 432
refutedMozart’s circle sits at around 421 Hz. Hendrix tuned a whole semitone lower — 100 cents, not 32; that is a transposition, not a question of reference pitch. Marley’s instruments were built fixed to 440.
432 matches the earth’s frequency (Schumann resonance)
does not add upThe Schumann resonance lies at about 7.83 Hz and fluctuates. Raised by octaves it gives roughly 501 Hz, not 432.
440 Hz was imposed for political motives
refuted440 Hz was already recommended in Stuttgart in 1834, long before the conference of 1939 — which was organised by the British, with French participation.
528 Hz acts on cells or on DNA
no basisThis claim comes from the same book of 1999. There is no published experimental basis for it; the frequently cited chain of evidence dissolves on inspection.
What the research supports
It is well established that music as such reduces tension — before medical procedures, for instance. There are systematic reviews for that with several thousand participants.
That does not hold for a specific advantage of 432 over 440. On that there are only small pilot studies with eight to fifty-four participants, mostly from a single research group, without independent replication. The largest study so far (2026, 162 participants) even found a rather unfavourable picture for 432. There is no meta-analysis.
That is not a statement against 432 Hz — it is the observation that the evidence for the big promises is missing. As a musical option, the lower tuning remains valid, interesting and entirely harmless.
What this means for lessons
This is where the question becomes concrete — and where a conversation with the teacher pays off, because the answer depends on the instrument.
Listening to music at home in 432 Hz: entirely harmless. It is the same music, a little lower.
Can be tuned to any reference pitch. But someone who practises alone at 432 and then sits at 443 in the ensemble trains their ear on a reference that does not apply when playing together.
Are built around one reference pitch and adjustable only within narrow limits. Switching to 432 is not a matter of taste here; it comes at the cost of intonation.
The reference pitch is not a setting but a job for the piano tuner — and going back and forth frequently is neither sensible nor cheap.
The practical heart of it: recitals, exams, orchestra and accompaniment all run on the customary pitch. A child working towards that needs a reliable reference there.
As a listening experience there is nothing against 432 Hz. As a practice tuning for a child who plays with others, practical considerations speak against it.
Listen for yourself
The most honest way is your own comparison, and a blind one — that is, without knowing which version is playing. This is exactly the point at which many claims grow quieter.
The listening test runs in the browser, without signing up and without installing anything. It claims nothing and reports honestly — including when you hear no difference.
And for anyone who wants to experience the difference not in a test setup but in music they actually like: IYAMBAE FM is an ad-free internet radio that retunes any of its stations to 432 Hz on request.
Where these figures come from
Historical pitches: Alexander J. Ellis, “On the History of Musical Pitch” (1880); Bruce Haynes, A History of Performing Pitch (2002, around 1,400 instruments measured). Milan 1881 and Verdi’s position: Gazzetta musicale di Milano, 13 Nov 1881, and the Verdi–Ricordi correspondence. Viennese pitch: Clemens Hellsberg, “Gedanken zum Stimmton” (2016). Solfeggio frequencies: L. G. Horowitz and J. S. Puleo, Healing Codes for the Biological Apocalypse (1999). Research: Cochrane reviews on music and anxiety (2013/2021) and the individual studies on 432 and 528 Hz up to 2026.
All frequency and cent figures have been recalculated. This page deliberately makes no claims about health effects — the basis for such claims is missing.