In the 1970's, Firesign Theater was very popular on college campuses. Small quotations from them (such as, "They think he's insane, yet he outranks them. His option: COMMAND!")were shouted across classrooms and featured on homemade signs at rallies. I never saw this video: to me Firesign theater was always voice acting, but the records were playing nonstop. According to Wikipedia, some comedy writers consider Firesign Theater to be the "Beatles of Comedy."
This particular clip is a mock public service announcment about aliens landing. It might not grab you at first: watch it and let it, let time pass, and watch it again. It's addictive.