The animation begins with a child singing the ABC song, while text in the box in the middle morphs into each letter or line of the song. This goes normally for most of the song, but as the child sings, "Next time won't you--" they get cut off by a masculine voice yelling, "Five!" as the screen rapidly flashes back and forth from black to red. While the screen is flashing, there is a giant number 5 in the middle flashing the opposite color from the background. The animation ends with a story about how this happened on a syndicated airing of an episode of Sesame Street, which the creator made made up. The entire ABC song (without being cut off) can be found in the Flash file.
This version is safer, with lowered volume and frequency of color change.
NOTE: The following video contains a screamer with flashing lights!