Lux Aeterna is a choral piece composed by György Ligeti in 1966 and gained mainstream recognition after being featured in Stanley Kubrick's film "2001: A Space Odyssey" in 1968. The composition is part of Ligeti's larger work called "Requiem," which he never completed. Lux Aeterna is characterized by its intricate harmonies and use of micropolyphony, a technique that creates complex and dense sound textures. The piece consists of a six-part choral arrangement, and its ethereal and otherworldly qualities evoke a sense of awe and mystery. Lux Aeterna has since become widely popular, finding its way into various films, commercials, and even modern classical performances, contributing to its enduring legacy in the musical landscape.