The chant is a metronome, not a spell
Light as a feather works because four people lifting together carry 15 kg each. The rhyme's real function is to synchronise them.
- audio
- editing
- non-diegetic-sound
- atomic
- ritual
Four people lifting an 80 kg body take 12–20 kg each — easily within finger strength. The lift fails when participants pull at slightly different moments, and succeeds when they pull together (The history of "light as a feather, stiff as a board").
So the chant is a timing device. Its supernatural claim is false and its practical function is real: it gets four people onto the same beat. Samuel Pepys recorded the game in the 1660s and the witnesses were already testing it for fraud by repeating it on a heavier man.
Why this belongs in a film wiki. The scene in The Craft — light as a feather does the same thing to the audience that the chant does to the girls. The cutting is locked to the rhythm, the repetitions accelerate, and suspense is manufactured out of pulse rather than information. It is a rare case where the ritual depicted and the technique depicting it run on identical machinery.
An Audio case. Compare Herrmann scored the shower against orders — suspense from a composer's cue laid over the image, versus suspense from a rhythm the characters are producing themselves. Both are Non-diegetic sound questions from opposite directions.