Kay Rasmus Nielsen was a Danish illustrator who was popular in the early 20th century, the Golden Age of Illustration which lasted from when Daniel Vierge and other pioneers developed printing technology to the point that drawings and paintings could be reproduced with reasonable facility. Nielsen is also known for his collaborations with Disney for whom he contributed many story sketches and illustrations, not least for Fantasia.

Fantasia is a 1940 American animated musical anthology film produced by Walt Disney Productions, with story direction by Joe Grant and Dick Huemer and production supervision by Walt Disney and Ben Sharpsteen. It consists of eight animated segments set to pieces of classical music conducted by Leopold Stokowski, seven of which are performed by the Philadelphia Orchestra. Music critic and composer Deems Taylor acts as the film's Master of Ceremonies who introduces each segment in live action.