I just did a search to find out if there was a difference between 528Hz & 444Hz & while I didn't answer my question, I did find a good overview. Written by a "non-conspiracy-theorist", lol, who says he is writing for the fun of the topic. Gives a good history, and then goes on to explain. Hope it helps if anybody is curious.

https://ledgernote.com/blog/interesting/healing-benefits-528-hz-solfeggio-frequencies/