Will and Mango get serious about novelty songs, learning: why there was a Golden Age of this unique music; how the Monster Mash got invented; who was really doing the kung-fu when "everyone" was kung fu fighting; and why a song about Itsy-Bitsy, Teeny-Weeny, Yellow Polka Dot Bikinis isn't what you think it is. Plus: Will and Mango reveal two shocking truths about The Purple People Eater.