In the early 1930s, film sound technicians created completely synthetic sound by drawing or photographing patterns on the soundtrack area of the filmstrip. Several artists in Germany, Russia, England, and Canada used this innovation to write what came to be called "animated music" or "ornamental sound." It was featured in a few commercial and small artistic productions and was enthusiastically received by the public. It was heralded as the future of musical composition that could eliminate performers, scores, and abstract notation by one system of graphic sound notation and mechanized playback. Its popularity among mainstream filmmaking did not last long, however, due to its limited development. The artists drawing animated sound were dependent entirely upon their technological medium, and when the sound-on-film system faded from popularity and production, so did their art. By examining from a musicological perspective, for the first time, specific examples of animated music from the work of Norman McLaren, Oskar Fischinger, Rudolph Pfenninger, and several filmmakers in Russia, this thesis enumerates the techniques used in animated sound. It also explores the process of its creation, adaptation, and decline. In doing so, it reveals an important chapter in the little-known early history of modern synthesized sound alongside the futuristic musical ideas it both answered and inspired.