Let It Grow is the closing musical number from Illumination's 2012 animated film The Lorax, performed as the town of Thneedville finally embraces planting trees and restoring nature. The clip spread online as a meme sound, especially in short-form edits and bass-boosted versions that exaggerate its already triumphant chorus for comic effect. It remains popular because its instantly recognisable melody and hopeful message work as a shorthand for growth, redemption and a satisfying ending, even for viewers who have not seen the film.