The films of UPA are surprisingly well rated on IMDb despite the fact that the animation quality is light-years behind that of Looney Toons, Disney and MGM at their prime. Sadly, due to rising costs in making pretty cartoons with high frame-rates and lovely backgrounds, the UPA style (which debuted about 1950) began to dominate in the late 50s and 60s. After all, the films were dirt cheap to make and they'd received several Oscars to "prove" that the cartoons were now mainstream. So as a result, lousy animation was becoming the norm and this trend wasn't reversed until the 1980s.
This UPA film is one of the early ones. The characters are very simply drawn (any simpler and they would have used stick figures) and the backgrounds were ugly--simple line drawings with colors added in a very slap-dash manner (often with a sponge and rarely completely filling the items).
As for the story, it's a jive story with a strong jazz style attitude. Some will love this, others will just find it very, very loud. It's the traditional "Frankie and Johnny" story and because of the shootings and all, it's probably not a great film for the kids. Heck, because of the animation and jazz, it's not a particularly good film for me, either! Some will read my review and no doubt think I am a crank (which I am, to a degree). However, I love animated films and a little of this minimalistic UPA style goes a very, very long way and you can't seriously consider them great works of art--just very, very quickly made cartoons. Ignore the Oscars and try watching some classic cartoons or something--anything else!