I remember that a lot of early stereo pop LPs were like that, voice on one side and accompaniment on the other. The first couple of Beatles albums, for sure. Can't remember what else. I thought it was really cool, having grown up on Mono. I don't think I regularly started buying Stereo recordings until I was in college and when these early pop LPs first appeared in Stereo it was trippy to listen to them with headphones, sometimes with certain chemical listening aids. Back then albums were available in both Mono and Stereo versions, and usually the Stereo LPs cost a bit more. Never knew if it was a naive approach to engineering or maybe some sort of gimick to get people to junk their Mono equipment and buy Stereo.
Perhaps someone even older than me knows....
Perhaps someone even older than me knows....