The plot synopsis says the visuals are an "artistic representation of the sound track".
I'd venture to say that the visuals ARE the soundtrack, optically printed into the frame. The frequencies look correct, and the widths look like normal 35mm soundtracks. Given that McLaren often hand-painted his soundtracks, this would not be too far a stretch. It would have been a simple matter to use an optical printer and expose the tracks in the picture area of the film. This was my first thought when viewing the film. I can't imagine him painting the soundtrack, and then going back and making pictures over again to "represent" the track, when the artwork was already there for the taking.
I'd venture to say that the visuals ARE the soundtrack, optically printed into the frame. The frequencies look correct, and the widths look like normal 35mm soundtracks. Given that McLaren often hand-painted his soundtracks, this would not be too far a stretch. It would have been a simple matter to use an optical printer and expose the tracks in the picture area of the film. This was my first thought when viewing the film. I can't imagine him painting the soundtrack, and then going back and making pictures over again to "represent" the track, when the artwork was already there for the taking.
