Micropolyphony is a type of 20th century dense musical texture that simultaneously uses multiple parts with differing tempos, rhythms and timbres to create sustained, but gradually shifting, dissonant chords. The chords resemble cluster chords except that they are continuously transforming rather than being static. The individual parts are intertwined and the texture so dense that the former are no longer discernible by the human ear and instead create a "cloud-like" or "dreamy" quality.
Micropolyphony can be applied to any desired instruments or combination thereof, including orchestras, choirs and solo voices. It is easier to accomplish with larger ensembles and with polyphonic instruments such as the piano.
Micropolyphony was developed by György Ligeti, who employed it extensively during the 1960's and 1970's. Perhaps the best known example is his Requiem for Soprano, Mezzo-Soprano, Mixed Choir, and Orchestra, because of its use in Stanley Kubrick's 1968 epic film 2001: A Space Odyssey.