What was wrong here

Verdi: first 435, later 432 — our own correction was too brief

Our correction from September was true only for the 1870s. For the congress of 1881 Verdi sent Boito to argue for 432, and in 1885 he called 432 the more correct number — we quote the letter ourselves. He gave it up so that there would be a common pitch at all. What still stands: “Verdi tuning” as a slogan is an invention of the late 1980s.

Nineteenth-Century Music Review 22 (2025), pp. 346 and 358 · Carteggio Verdi–Boito, letter of 8 November 1885

Studies next to the download button — and a sentence that sounded like an effect

The section with the studies sat on the page where the Tuner is available. It does not belong there: whoever lists studies on pulse and cortisol next to the download button turns reports into a sales argument — even without meaning to, even when they say “undecided”. It now sits on the page for parents, with the authors’ caveats; the home page now says only that there is no scientific consensus and that we therefore promise nothing. One sentence was reworded in the process: “worked equally well” sounded like an effect against anxiety. All that was found is that 432 and 440 did not differ — and no more than that is there now.

Aravena et al., J Appl Oral Sci 28 (2020), e20190601

A cortisol figure the data do not support

We had taken the numbers from the abstract of the study, not from the data. Reading the full text showed: the 1.35 is the starting value of the 440 group, not its final one — we had mixed up beginning and end. And the changes within the groups were none of them statistically sound; the 432 group started out at half the value already. With fifteen people per group, the difference in final values is in all likelihood an accident of how the groups were drawn.

Aravena et al., J Appl Oral Sci 28 (2020), e20190601 · independent review, University of Padua, 2023

Milan was 1881, and Verdi cared about unity, not about a number

Two errors in one line. The Congresso dei Musicisti Italiani met in June 1881, not 1880. And Verdi had no fixed number: in the 1870s he campaigned for the French 435, in 1884 he accepted 432 because the difference was “so small, almost imperceptible to the ear”, and in 1885 he called 432 the more correct number — but let it go so that there would be a common pitch at all. The battle cry “Verdi tuning” for 432 only arose in the late 1980s, long after his death.

Gazzetta musicale di Milano, 13 Nov 1881 · Carteggio Verdi–Ricordi 1882–1885 · Rosenberg, J Popular Music Studies 33 (2021) · Carteggio Verdi–Boito, letter of 8 November 1885 · Nineteenth-Century Music Review 22 (2025)

A caveat missing that the authors state themselves

On the study that found a lower pulse at 432 Hz, one sentence was missing: the authors write themselves that they cannot say whether this is down to the number 432 or simply to its being lower. The study still reports it; what it means is open — the qualification belongs with it, and it was not there.

Hohneck et al., BMC Complement Med Ther (2025), PMID 39844155

A version number twenty releases old

It was never visible: the entry sits in the structured data and is read only by machines. That is precisely why it went stale unnoticed — for search engines the Tuner was a 0.1.0 for months while the page offered a 0.21.1. A number nobody sees is a number nobody checks. It now comes from the same line as the button; if the link is missing, the build stops.

“Measured”, where nothing was measured

The radio assumes for every station that it sits at 440 and takes off a flat 1.8 per cent. Nothing is measured there — and three other places on the same page say so explicitly. A word in the status line that contradicts that costs more than truth; it devalues the very argument by which we set the Tuner apart from everything else.