I don't know anything about it, but do these theories seem true to you? And if playing at 432 Hz is truly beneficial, can one change the tuning of their own piano? I invite you to watch the following video and read the following explanations, which are not my words but those of the person who uploaded the video.
is it possible to disharmonize society, putting human consciousness to sleep, by using sound as a natural tool?
Since 1939, when the Masons (including Wagner and Russian and Austrian military bands) decided to use 441 Hz as the standard frequency for sound, society has undergone serious upheavals in its entirety.
The 441 Hz frequency, used by radio, CDs, mass media, and television, is highly harmful to our brain and our well-being: this type of disharmonious vibration acts as a carrier of stress, anxiety, and various types of pathologies.
On the contrary, the 432 Hz frequency, used by the greatest composers such as Giuseppe Verdi, Mozart, Beethoven, and Pink Floyd, proves to be much more pleasant and touches the sensitive points of our brain with greater precision compared to the now universal tuning fork at 440-441 Hz. In fact, it acts as a relaxing, calming, meditative, anti-stress agent, as well as a deterrent for the various pathologies that affect our body (due, as is not unknown, to a perception of negative frequencies).