My analog keyboards use analog multiplexers (74HC4067) which is similar to how shift registers work. Except they're full of flip-flops (2-way) instead of digital logic.
I made two videos talking about how I design my analog keyboard PCBs and how I'm using analog multiplexers here: https://youtu.be/TfKz_FbZWLQ
I made two videos talking about how I design my analog keyboard PCBs and how I'm using analog multiplexers here: https://youtu.be/TfKz_FbZWLQ