Well, as a fun side-project I messed with reprogramming #SnapCircuits a bit.
Figured out how to reprogram the #PICAXE micro in the LED MC (U29) black box using the PICAXE software and a custom soldered adapter (the original is no longer sold).
Today I got it to take input from the Keyboard (U26). It outputs a square-ish wave that is then smoothed by the speaker, so I just using the pulsin instruction to measure the pulse length and interpreted that according to the markings on the keyboard.
Here's a POC, very rough but I'm bored and don't want to spend more time:
https://gist.github.com/JJTech0130/38ea29836538f541a3195da6cdf6d7f6