NOTATIO

I just came across this video demonstration of Mockingbird, which it turns out is the first "WYSIWYG' notation editor, created by researchers at Xerox PARC in 1980. They even hooked up a synth, before MIDI.

https://www.youtube.com/watch?v=0dxaEDKoTys

The beaming might be a bit suspect, but it's surprisingly capable, and much is familiar.

Warning: contains contemporary hairstyles.