Sound and music con­sist of vibra­tions, the more vibra­tions per sec­ond, the higher the pitch. The unit for this is the Hertz, abbre­vi­ated Hz.

432 Hz is the nat­ural “musi­cal pitch” in the uni­verse, as opposed to 440 Hz, which is the stan­dard in the music nowa­days in, for exam­ple, music albums and mp3 files.

This musi­cal pitch is the stan­dard pitch of the dia­pa­son, which is the musi­cal note A above the mid­dle C, sci­en­tif­i­cally named A4.

In 1939 Ger­many and Eng­land deter­mined 440 Hz as the fre­quency of the musi­cal pitch, after first rec­om­men­da­tions in the 19th cen­tury. Their effort to stan­dard­ize this world­wide didn’t suc­ceed for then. But in 1953 at a con­gres of musi­cians in Lon­don, 440 Hz still became the inter­na­tional ISO 16-standard. Many protests of (among oth­ers) French musi­cians, who wanted 432 Hz as the stan­dard, didn’t help unfortunately.