I heard a recording of Floyd playing Dark Side before the album was recorded. On the Run was guitar and not EMS VCS3 based. Seems as though there were a couple other differences, but it’s been awhile since I heard it.
Seems odd they would do on the run without a Synth since they created it with the Synth. Of course that was an extremely creative band and we’re not chained to any version of a song.
I remember hearing a bootleg once from the short period where both syd and David were playing guitar. Nice jam and then towards the end I finally recognized it. May have been set the controls. Don’t remember. That also happened to me when I saw the yardbirds in 1966. They are jamming and finally I realize they are playing I’m a man. Back then they jammed and changed things up a lot live.