Disney: The Skeleton Dance (1929)

The skeleton dance is a very early hand drawn disney short film. It is said to be the first ever music video. It feature choreographed dances, and graveyard alternatives to orchestral instruments replicating sound from the original score. Its can be called the first "music video" its the first animation to have the soundtrack as preproduction rather than post this means the animation was created for the musical score instead of working the other way round. I found this very interesting because nothing like this was made for quite a while after this but music videos for a few decades have seemed almost obligatory for popular musicians.