This is very cool. I might have the skills to replicate this but would never be able to accomplish it. My brain is warped .. to get motivated, I need the end result to be of some tangible value. Pure fun doesn't work for me, sadly. I am also unable to go and learn something just for the sake of learning.
Just an aside, an I realize efficiency is NOT a metric for your fabulous display .. here is another interesting mechanism. Maybe one could build a 10K or 100K display with this?:
Oh yeah I love split flaps! Even considered them for this project but they're cost prohibitive and that idea is already out there.
The sound those things make is just perfect.