IN 1935, the British General Post Office commissioned an advertisement from the New Zealand–born artist Len Lye, who was based in London at the time. The resulting film is a mere four minutes long, a small gem of an animation titled A Colour Box that sends a joyful riot of dots and lines dancing across the screen to a festive soundtrack of beguine, a jazz-inflected type of West Indian dance music. It’s hard to imagine just how gratifying the protopsychedelic film would have been to watch in the midst of the Depression, but it enjoyed a wide run as a preview reel that played before commercial