Another fun fact: They were often not A side and B side on a single disc, but something like A side and F side. You put the whole stack on the record player spindle, it feeds one down, plays the top side, feeds the next down, play the top, and so on. Then when all the top sides were done you flipped the whole stack over and did it again. Each 78 only had enough room for about 5 minutes per side.

My grandparents had a number of these.