ProdigalFrog

MIDI.

Before the 80’s, there was no standard interface to control electronic instruments, just a bunch of proprietary interfaces unique to each manufacterer. But in 1983, amazingly they actually standardized on MIDI, and it remains a useful standard to this day, with any new versions of MIDI being completely backwards compatible, so your Yamaha DX7 from the 80’s is still just as viable to use today as the day it was new!