A24's New Horror Movie Undertone Was Secretly Inspired By A Classic Children's TV Series

Warning: Mild SPOILERS lie ahead for Undertone!The world of A24's Undertone primarily pulls from creepypastas, but a classic children's TV series also had a hand in its creation.

Hailing from debuting writer/director Ian Tuason, the horror film centers on a pair of paranormal podcasters who, upon receiving 10 mysterious audio files, find themselves the target of a malevolent spirit. The Handmaid's Tale alum Nina Kiri leads the film's cast as one of only two people seen on screen, with the rest of the roster including Overcompensating's Adam DiMarco, The Virgin Suicides' Michèle Duquet, The Hardy Boys' Keana Lyn Bastidas and Jeff Yung.

Now, in honor of the film's release, ScreenRant's Grant Hermanns interviewed Ian Tuason to discuss Undertone. When asked about one of the A24 horror movie's biggest elements being hidden messages in children's songs, the writer/director began by denoting his love of creepypastas, as he's often "scouring the internet for things that scare me," and often finds them to "scare me more than any movie that's come out."

It was during this research that Tuason stumbled upon one "that found a hidden message in a rock song," to which he himself took to listening and "started to get scared even before I heard anything." This sent him "deeper down the rabbit hole" of research, in which he eventually "found a Sesame Street song that had a hidden message and that scared me more," leading to him realizing to "go younger" with songs that may hold hidden messages:

Ian Tuason: No, but I remember Kermit was in it. And I loved it so much because of what the hidden message was that I started writing Undertone to that song. I went a good two days writing it to that song instead. But then eventually, I was going to finance it myself, so I knew I couldn't get the rights. And I said, "D--n it." But then I found "Baa, Baa, Black Sheep" and "London Bridge," and that worked even better.

Though he may have changed strategy due to recognizing he likely wouldn't get the rights to a Sesame Street track, Tuason still found a way to turn childhood songs into terror for Undertone. "Baa, Baa, Black Sheep" generally serves as the main song for the movie's series of hauntings, tying into Evy's troubled relationship with her mother, which is part of what makes her a target for Abyzou's hauntings.

Evy isn't the only one who finds herself picking up on the hidden messages in kids' songs through Undertone's runtime. In listening to the mysterious audio recordings, DiMarco's Justin similarly begins hearing ominous ideas in "London Bridge," as well as messages meant for Mike inviting some kind of murder, none of which Evy herself hears.

What will be interesting to see now is how further down the rabbit hole Tuason may look to take the film's exploration of hidden messages in children's songs. The writer/director also confirmed to ScreenRant he has plans to expand Undertone into a trilogy, albeit was careful not to specify how the next two films would build on the mythology of the first.

Whether he elects to keep the narrative with Evy, Justin and the demon Abyzou, or move on to something entirely different, the auditory-driven format of Undertone leaves the door wide open for Tuason to go further and turn other classic children's songs into terrifying set pieces that play with characters' psyches. And if the first A24 horror film proves to be a true box office hit, there's still a slight chance the writer/director could bring back his original source of inspiration by incorporating Sesame Street into the mix.