Basically somebody describes a concept, maybe gives a little backstory, tells us what it's called in that universe., along with it's OTL equivalent.
my idea
Musiciacta (soundtrack, in OTL)
A corrupted version of Musikgeschichte (literally "Music Story," in German)
Originated in the 16th Century CE when a composer set a translated version of the Anglo-Saxon saga Beowulf to music. He then hired a local man to give a dramatic reading of the saga as his orchestra played the pieces he had written. Eventually adopted further afield, especially when an English composer set the works of Shakespeare to music. By the nineteenth century, many plays were being written with the musiciacta in mind. Adopted early-on in film, many composers would find employment writing musiciactas, and became household names as a result.