I've never believed that the synchronicities between Pink Floyd's Dark Side of the Moon and the movie The Wizard of Oz were anything but a really interesting coincidence. I've watched the combination a couple of times, including one time that some coworkers and I set it up in our Hollywood Video store. There are some cool moments, to be sure, but not enough lines up for me to believe the band structured the album to work in this way.
That said, there is a synchronicity I do believe is intentional: I believe that "Echoes," the last track from (and entire second side of) Pink Floyd's Meddle, was written as an alternate soundtrack to a portion of Stanley Kubrick's film 2001: A Space Odyssey.
So here's the theory: in 1967 or early 1968, at the height of the band's psychedelic period, Kubrick allegedly approached them to score 2001. They refused, for some reason (Wikipedia says they'd had a bad experience scoring another film, but the first movie scored by the band, More, wasn't released until 1969, so I'm not sure I buy that), and later regretted this, after having seen the film. So later, when they were assembling Meddle for
a 1971 release, they rescored the last segment of the film.
The evidence is compelling enough that I believe it. The planetary alignment / eclipse imagery would become prevalent in the band's subsequent work, especially the afore-mentioned Dark Side of the Moon. The length of the song exactly matches the last section of the movie. And each scene within the finale matches with an equivalent, and tonally appropriate, shift in the music.
Ideally, you can set this up at home with a DVD of the movie and a CD of the album. Cue up the film to the title card reading "JUPITER AND BEYOND THE INFINITE" in that Futura font so favored by Kubrick (and in bold form by Wes Anderson). This will be a chapter stop on the DVD. Cue up the album to the beginning of "Echoes." Unpause both simultaneously. Be amazed. But if you haven't seen the movie before, prepare for spoilers, to the extent that a notorious head-scratcher of an ending can be spoiled.
If you don't have access to the movie or the album, some helpful somebody on YouTube has done the heavy lifting. Check it out below. And I suspect this version will miss some of the most excellent, split-second matches between the media, when Floyd's musical hits line up precisely with inserted freeze frames of hapless astronaut Dave Bowman (above) contorting his face in agony. Oh, and it's almost half an hour long. So watch it at home or be prepared to explain things to your boss.