Bach played on clavichord.
When Bach was composing music, pianos didn’t exist. Instead, Bach composed almost all his music on a clavichord which, while sharing similarities with a piano, sounds completely different.
When you hear Bach played on a clavichord, it changes your entire perception of his music—makes you realize how it was meant to be heard.
A very interesting instrument. The pedal notes especially are very resonant which adds a lot of character to the performance.
Legend has it Bach’s favorite instrument was the lautenwerck aka the lute-harpsichord. They are similar to the clavichord but have a rounded body, which gives the instrument a much softer tone. Bach supposedly owned 4. Here’s a short recording: https://www.youtube.com/watch?v=8z31MbF89-8
It’s also pretty amazing on steel drums.
Bach feels like he composed music for the person playing the instrument, as much as for the people listening to it.