MidiFlood by Paul Wolinski
A four-piano phase test. Headphones recommended.
More info: http://www.paulwolinski.co.uk/?p=287
Video: https://vimeo.com/116463255
Paul Wolinski is one quarter of 65daysofstatic. He
occasionally makes music by himself too. It tends to be full of noise, scruffy pianos and minor chords.