In Bruce Hayne's comprehensive A History of Performing Pitch: The Story of A, he says that over the last 400 years or so, concert A has varied from anywhere between 380 Hz to 500 Hz—the difference of a major third or greater on some parts of the keyboard. In 17th Century Germany, Bonus says, there were two dispositions for concert A, each referring to its own relative pitch: the chorton referred to the high-pitch A that floated around 460 Hz and the kammerton, or chamber pitch, was around 416 Hz on average.
For Mozart, A was 421 Hz, while organs said to have been played by Bach in Leipzig, Hamburg, and Weimar were pitched as high as A=480 Hz. In This Is Your Brain on Music, cognitive psychologist and neuroscientist Dr. Daniel Levitin explains that the exact frequency of concert pitch itself really isn't a big deal when it comes to making music (except perhaps for singers whose instruments have their own unique limitations), which explains its movement over time.
"We can fix pitches anywhere we want," Levitin writes, "because what defines music is a set of pitch relations. The specific frequencies for notes may be arbitrary, but the distance from one frequency to the next—and hence from one note to the next in our musical system [the intervals we discussed earlier]—isn't at all arbitrary."
It's unsurprising when Levitin says the storied power of A432 is "a hoax that's been around a long time. Most a capella groups drift away from A440 anyway," he continues, "and no one associates that with either demonic or heavenly qualities. The whole point of music is that the notes themselves are irrelevant to a very large degree—it is the relations among notes that give rise to music."
And even then, he doesn't see anything magical on the physiological level about Renold's tuning system: "Neurons are tunable — that is, they can easily adapt to any tuning scheme." There is no evidence, he says, that different tuning systems give rise to new emotions or different emotions. In Levitin's view, expectation plays a big part in how music affects emotion. 432ers might anticipate a more relaxing listening experience when music is transposed to their preferred frequency and so any perceived difference might actually register in that way.
"They expect it to sound different and so it does," Levitin says. "Old violins don't actually sound better, people simply expect them to."
Similarly, University of Conneticut neuroscientist Dr. Ed Large says he's not aware of any evidence that suggests, as Renold claims, that one pitch could inspire spite and another good will. Large is interested, however, in the advantages of small integer ratio relationships in intervals. Even Collins, Mr. 432, says, "the ratios have everything to do with how resonance affects us consciously." Although when Large says it, he's demeaning the whole premise that 432 is at all special.