The Twilight Zone premiered on CBS in 1959 as Rod Serling's anthology of science fiction, fantasy and horror. Its first season used a Bernard Herrmann score, but from the second season onward the show adopted Marius Constant's now-legendary theme, the strange guitar figure everyone knows. Decades of reruns, revivals and parodies kept that motif in the cultural bloodstream, and online creators later turned it into shorthand for anything eerie or inexplicable, from glitch clips to conspiracy jokes.