Well I know a few of the obvious things. I know that in the Baroque era tuning was standardized from mean tone to well tempered tuning. I also know that the pitch was lower then than A=440 and today you can hear many “period” groups play to that tuning. A being higher than 442 seems to be European and I know a lot of groups have been tuning higher in recent years.
Does it all go back to Country of origin? Such as the CSO being a “German” orchestra so they take a German tuning etc..
If so how did those countries arrive at A= whatever.?
I have a masters degree and I can’t remember ever hearing about why different groups play at different A’s.
I guess this is what I get for skipping Music history to practice
