Nightmare on Elm Street:
The scene where the ginger girl is outside the others house singing is a reference to Freddy Krueger, who is a murder movie killer. In the 1984 film A Nightmare On Elm Street, he sings a creepy song similiar to this.
One two: Freddy's coming for you. Three four: Better lock the door. Five six: Grab your crucifix. Seven eight: Better stay up late. Nine ten: He's back again.