Interesting article on historical tunings.
This you tube video of Bradley Lehman playing and tuning from Bach’s “Das wohltemperirte Clavier” (1722) is included in the article. It is well worth a watch- the harpsichord has an exquisite sound!
Bach: Prelude in B major, on harpsichord – Bradley Lehman
Bach: Prelude in C, on Harpsichord — Bradley Lehman.