Pink Floyd
The cast would have included David Carradine, Mick Jagger, Udo Kier, Salvador Dali and more
In addition to the spectacular visuals Jodorowsky was putting together, his cast was going to say the least. In the lead role of Duke Leto? David Carradine (about whom the director reveals a hilarious story involving vitamins) but that was about the only traditional actor in the bunch aside from Udo Kier, who was going to play Piter De Vries. As for the rest? Well, Mick Jagger agreed to take on Feyd-Rautha, Orson Welles was to play Baron Vladimir Harkonnen and Brontis Jodorowsky (yes, the director's son) was going to play Paul Atreides. 

But perhaps the greatest coup was landing Salvador Dali, who made the rare decision to take a role in the movie, playing Shadom Corrino IV, the emperor of the galaxy. But he was making outrageous demands from the start, including a pay rate of $100,000 per hour as well as wanting input on the visuals of the scenes (Jodorowsky worked around this by welcoming Dali's input, while planning to only use him for one hour, and replacing his character with a mechanical robot that would be explained in the script). Dali's muse, Amanda Lear, was also given a part as Princes Irlan. All told, had that actually gotten through, it woulda been a helluva red carpet.

Pink Floyd and Magma were sought for the soundtrack
The music of the movie was going to be similarly epic as well. Jodorowsky's plan was to have a different artist compose a score for each planet in the "Dune" universe, with Pink Floyd sought as well as French prog rockers Magma, for the Planet Harkonnen. 

Alejandro Jodorowsky thinks his version could still be an animated film...
As the movie reveals, pre-production on "Dune" had reached the point where they were ready to start building sets, but ultimately, they couldn't find the cash to make the movie. Part of this may have been nervousness on Hollywood's part, but the also the sheer hubris of Jodorowsky's film which would have neared the 12-hour mark. Nevertheless, he was still heartbroken the movie couldn't get made, but it's influence lives on. The comic book series "The Incal" by Moebius and Jodorowsky, features some of the visual influences that would've been used on the film, and as the documentary highlights, lots of the work done on "Dune" was appropriated for other pictures ranging from "Flash Gordon" to "Prometheus." (The doc provides some interesting artwork-to-scene comparisons to make the case).

While Jodorowsky himself won't be making "Dune," he states that he believes another director could take on his work, and produce his vision as an animated film, something that would certainly be a much more realistic prospect. But perhaps this movie best exists in dreams...there are plenty more fascinating factoids to be found in "Jodorowsky's Dune" which will hopefully find its way to these shores soon.