Advent 2021, Day 15 - Nutcracker 3

78 rpm records were originally made from shellac. In the 1940's, however, the war effort required the use of shellac and it's use was restricted. This led to the record industry looking for new materials which, ultimately, led to the use of 'vinyl' for records which, in turn, helped bring about the advent of 33 1/3 rpm records. The "long play," or "LP" records could hold a whopping 22 1/2 minutes of material on each side, which became the norm by the 1960s.