The tradition of using shift registers for automated music generation very much lives on! These days they are typically called "Turing Machines" (I know, kinda of confusing for us CS folks), due to the influence of a popular version which came out in 2012: https://www.musicthing.co.uk/Turing-Machine/
The most common use of this recirculating shift register technology are those little flickering LED lamps used to simulate candles. That's how the pseudorandom flicker is generated.[1]
