In that case, it's fair to say that classical music conformed to the previous tuning standards. nostr:nprofile1qqszsshrfpsvt806e4wlfza85egxtenkp5yvxhmhj4fas0pvyvgtfycpp4mhxue69uhkummn9ekx7mqpzpmhxue69uhkummnw3ezumrpdejqlvnek5 tells me that 528 is the frequency of love. (I admit I never checked that)...

Before classical music (baroque and further back) tuning was also pure and not even temperment tuning. Modern pianos and guitars would be considered out of tune by those past standards.