Okay guys. Please explain to this old man. I know of what you speak. That the majority tunes to 440..... But at the end of the day. Isn't an A still an A? My question is. What makes the different tunings actually different?
There is a whole lot of conspiracy things, natural frequency healing things, older theories about how we used to tune before the governments of the world made us change it to 440.
There are cool little graphs that show 432vs440 and what designs they make based on their frequencies etc etc. maybe those things work for you, maybe they don't. I'm not super into much of those reasons for the change.
I tried it yesterday with my most finicky guitar I own, and it immediately and effortlessly tuned right up... perfectly. It seemed to really make a difference in how the instrument responded to the minor adjustment in where it was tuned. It became a little livelier and sounded more rich.
I was immediately impressed with "my own 2 ears."
For this reason I have become a believer in the 432.
Today I will go out to the garage, adjust tunings there (drop B guitars) and test out this theory of 432 is better. 8hz is a minor amount of change, but what if all the hype is really true?
There are lots of good (and some sarcastic) videos on the topic on YouTube as well.