A pet project...
But the more you think about it, the more amazing an accomplishment this number seems. The cage must have had a diameter of something like 20 feet, and the light fixtures had to stay powered throughout. The whole thing must have weighed a ton or two. Building this set was an enormous feat of engineering. What would it look like to a bystander as this amazing scene was shot?
To try to answer that question, I took the scene from the movie (left) and performed a little video trickery (right). I did three basic things:
1. Stabilize the footage. I tracked the light fixture in the middle of the back wall, and kept it stationary onscreen while the camera frame moved around it.
2. Recreate the room. I took stills from throughout the sequence, looking for Fred-less fragments of the set that I could piece together to make one "clean" image of the entire room. I also made two image “patches” so that the photo could appear in both the locations Astaire leaves it during the sequence.
3. Rotate the room. I put the stabilized footage on top of the recreated room, and then tried to figure out exactly when the room was being rotated. Admittedly, there was a bit of guesswork here, but I've got it more or less correct. I tried to err on the side of restraint, only rotating the room when it was inarguably so. It seems to take about 4 seconds for the huge cage to rotate 90 degrees.
In creating this, I of course watched the dance many times, and have a few observations:
0:27 - Astaire twirls the desk chair around here; after the cut at 0:37, this chair would be bolted down so it would rotate with the room. And it must have been attached quite firmly too, since Astaire hangs from it at 1:40.
0:55 - There are several moments like this one where Astaire seems to play with the notion of “defying gravity”. It's certainly possible that the room was rotated counterclockwise just a bit at this point. But from much experimentation with the timing, I think it's more likely that the room moved definitively in increments of 90 degrees only. (See note at 2:45 below.)
1:39 - Notice that when Astaire lands on the "ceiling" after jumping the light fixture, one of the fixture's lights blinks on. Was there an electrical short?
1:42 - With a bit of a tug, Astaire pulls the photo down from the desk. What kept it in place? Magnets, according to Stanley Donen.
1:45 - There's a camera shake (probably due to the set beginning to rotate), and the ceiling light that came on at 1:39 goes back out.
2:17 - There's a fairly obvious cut here to a closer shot. This number feels like one continuous take, but in reality the dance section is pieced together from three different shots. (See 2:45 below.)
2:19 - Astaire now casually places the photo against the right wall, where it will stay in place magnetically while the room is rotated again.
2:45 - Another cut. This is quite a remarkable one, as it passes by virtually unnoticed as one watches the scene. Both Astaire's positioning and the camera framing were extremely close from one take to the next, making the cut almost undetectable. It’s interesting to note though that throughout the number, the room rotates 360 degrees clockwise, then 270 degrees counterclockwise, then 270 degrees back clockwise. Before it switches direction each time, there’s a cut. Was it necessary to somehow “shift gears” on the rotating cage to get it to switch directions, which necessitated these cuts? If so, it's a strong argument against any counterclockwise rotation at 0:55.
3:30 - Astaire easily snatches up the photo again to bring the number to a close.
My goal here wasn't to "spoil the secret"; as I say, I think it's fairly well-known how the scene was accomplished, and not too hard to figure out anyway. I just hoped to make it a little easier to visualize what went into the making of this piece of Hollywood history.
While the filming of this number was apparently entirely undocumented, Donen recreated the effect in 1986 as part of Lionel Richie’s “Dancing on the Ceiling” music video. I’ve edited the relevant excerpts from the video’s “making of” documentary and posted it below; this is the best idea we have of what filming Astaire’s number must have been like.