This was great.
I always recommend watching his old Chipophone video (homemade 8-bit synthesizer from a repurposed old electronic organ). He has made many cool instruments since. Some of which maybe more tehcnically impressive, I can't tell. But this one is probably still on my all time top 10 "most enjoyment from watching a Youtube video" https://www.youtube.com/watch?v=m1pchpDD5EU
Such cool sounds and he plays it well!