also the musical scales and tuning systems Bach used were different.
He worked with unequal temperaments (like well-tempered tuning), allowing all keys but with some altered intervals, unlike today’s equal temperament, and his music used more flexible minor scales.
“He worked with unequal temperaments (like well-tempered tuning)”
How is music played when a nonstandard temperament is used? A piano is always tuned to the standard, isn’t it? If not, music would sound different and unpleasant if played in different keys.