The great Gene Kelly spent a lot of time dancing on movie and TV screens, occasionally with animated characters. The best sequence to meld him and a cartoon was in the 1945 film Anchors Aweigh where he performed with Jerry, the famous mouse from the "Tom & Jerry" franchise. Like most of those films, the sequence in Anchors Aweigh was animated under the supervision of MGM animation producer-directors Bill Hanna and Joe Barbera.
Flash forward to 1967. Hanna and Barbera now had their own studio producing cartoons primarily for television. Budgets in TV were way lower and time was much tighter. When Bill and Joe's outfit produced a prime-time animated TV special of Jack and the Beanstalk, it was largely written around a character played by Mr. Kelly. That made it just about mandatory that in one sequence, he would dance with one or more animated characters. Could they possibly top or even equal the beauty and technical grace of the number in Anchors Aweigh?
No, of course not, you big silly. I doubt they even thought that was humanly possible; not on a TV budget with a TV production schedule. As with most things that came out of that studio, the optimal goal was to do the best they could, given the time and money they had to do it with…and I'll give them this: They got pretty decent songs for the special. This, they achieved by hiring the team of Sammy Cahn and Jimmy Van Heusen — the same guys Sinatra used. The animation was a bit less impressive but generally it served the story fine.
Below is the dance number in which Gene Kelly dances with two "Woggle Birds." The speaking voices of the birds were done by Leo DeLyon and Cliff Norton but I'm not 100% sure they did the singing voices. H-B loved to dub singing voices with professional singers, which is why Yogi Bear and Boo Boo don't sound like themselves when they sang in the theatrical feature, Hey There, It's Yogi Bear. In this Jack and the Beanstalk special, Jack was played by child actor Bobby Riha but his singing voice was supplied by actor Dick Beals, and Janet Waldo voiced a princess whose singing voice was that of Marni Nixon. Gene Kelly, of course, sang for Gene Kelly.
I believe they filmed this number by having one or two dancers on the stage with Kelly. They could have done it with one guy dancing for one of the Woggle Birds and then duped and flipped the animation traced off that guy's movements. Or they could have hired two actors — one for each Woggle Bird — and then traced from either. Clearly though, most of the animation of the Woggle Bird on one side of Gene is a mirror-image duplication of the drawings for the Woggle Bird on the other side of Gene — or vice-versa. I'd guess they did it with one dancer…a guess I base on the fact that Hanna-Barbera never spent a dime if they didn't have to.
An animator (reportedly Ed Love) traced the stand-in dancer footage for positioning and timing. In the process of combining Kelly, the birds and the background, the image(s) of the dancer(s) was/were to be omitted.
Technically, it's a far cry from Anchors Aweigh or any theatrical intermingling of live actors and drawn actors. Mr. Kelly and his dance partners rarely seem to be on any floor or even on a consistent level. The video "smears" here and there and that's not a failure of the videotape or the transfer. That's the way it looked on the air. You'll also see black shadow mattes peeking out from behind the birds here and there and that may be intentional.
I have a 52-year-old memory of seeing this special when it first aired. I also have always had real sharp eyesight and the ability to spot things that are only on-screen for a fraction of a second so please take my word for this: I saw a few ultra-brief flashes of a human dancer peeking out from behind a Woggle Bird. They'd almost completely erased the person's image but a few vestiges remained.
H-B had a history of delivering shows to the network at the last possible moment. Even into the eighties when I worked there, shows would get on the air with mistakes and then they'd fix them (sometimes) for future airings. My theory is that when this show was first broadcast, I did see what I recall seeing and they went back and someone — probably Bill Hanna — asked "Okay, what's the cheapest way to fix that?" And some editor or engineer said, "We still have the various layers of video for this number. In the spots where the dancer shows, we could move the background matte a bit to cover him. It might look like a weird shadow or a weird video error but either way, you wouldn't see the dancer. Then we could recomposite the footage and edit it in."
Or maybe it went something like that. But I'm pretty sure I saw something that isn't there now. What is is kind of cute.