In the 1950s, the UPA cartoon studio was producing some of the most innovative animated shorts the field has ever seen for both theatrical exhibition and for various commercial usages. One of the ones they did that kind of split the difference was this version of Peter Cottontail, which appears to have been done mainly for airing on the legendary kids' shows that ran in Chicago. At least, I'd never seen it before it was put up on YouTube as a promotion for a new DVD of several cartoons produced for Chicago kidvid. I believe the legendary Grim Natwick was one of the main animators on this, and it features a particularly jazzy vocal arrangement of the song which you may enjoy. It runs two and a half minutes and the whole DVD can be ordered here. I'll be linking to other cartoons from it in the following week…