There is a nice little article in the New York Times about the Pink Floyd laser light show. It's been around now for four decades. Here's how it began:
In 1970 a California Institute of Technology professor asked [Ivan] Dryer, then a young Los Angeles-area filmmaker, to record her laser demonstrations on film. Mr. Dryer became hooked, spending the next three years developing his technique as a "laserist" for films and on tour with Alice Cooper. His dream was to put on a laser show set to music at the Griffith Observatory in Los Angeles, an idea that was repeatedly rejected by the city-owned planetarium until November 1973, when Mr. Dryer's company, Laser Images Inc., was given four Monday nights as a trial run. The shows sold out for weeks.
There were 12 recorded songs played during Laserium I, as the initial performances were called, with music from artists ranging from the Rolling Stones to Johann Strauss. On the set list there were also two Pink Floyd songs, "Set the Controls for the Heart of the Sun" and "Echoes," both from albums that neither sold well in the United States nor produced any hits.
And yet the music immediately connected with the laser audiences, Mr. Dryer said. "When I first heard their music I thought it was perfect for the kind of thing we were doing," he added. "It was instrumental largely, and we were looking for something that was not widely known."
What did soon become widely known was the laser show's success, and planetariums across the United States approached Mr. Dryer about building more laser machines. It was an arrangement that some later bemoaned, he said, remembering that several museums with planetariums did not take kindly to the shows' fans. "They were called 'the wrong element,' " he said. "It was always an uneasy marriage."
It's hard to imagine a world in which there were no Pink Floyd laser light shows.