I just found an article on the Giza pyramid saying one of the chambers was 438 or 440 Hz.
I had looked up the 442Hz I calculated and found some symphonies in Europe use that for concert A but others use the lower numbers like 438 and 440.
Anyway, this article is fringe material, but who knows? There are others articles if you search "frequency of pyramids"
http://www.gizapyramid.com/Leone1.htm