Before MIDI
As an electronic musician with more than a little grey in my beard, I remember the pre-MIDI days as well as the MIDI days, and the MIDI+digital days that came after.
Back in the old days, electronic instruments couldn’t talk to each other (I remember several times when it was all that I could do to get them to talk to themselves). This wasn’t seen as much of a loss; we didn’t know better, for one thing, and musicians were quite used to playing one instrument at a time as a rule.
So unless you stuck with one single company, or at best two or three that happened to recognize the same voltage specs, you were still playing one instrument at a time (okay, sometimes two…I’m no Rick Wakeman, but even I can handle a bassline with my left hand on one synth, and chords or melody with my right hand on another). That’s fine for studio work and most performances, so it wasn’t a big deal. Lack of patch memories and shaky tuning were a much bigger hassle, if I remember right!
However, a growing number of fellow experimenters saw the possibilities for both convenience and experimentation (not to mention increased opportunity for the control freaks and one-man bands, or anyone else who was a little tired of working with crazy drummers and contrary guitarists…and we won’t even get started about singers).