About all that can be said for Abisch and Kaplan's shows is that they are short and simple. Their ""Comedy Show"" consists of a string of elephant jokes fired off by two children dressed up as Jumbo and Dumbo in paper bag masks; the ""Country and Western Music Concert"" calls for an eclectic array of homemade instruments--including bongo drums, tambourine, and detergent-box banjo--to be played along with the recordings; and the ""Silent Movie"" (called ""Mrs. Snooty and the Waiter"") combines pantomime with titled dialogue that hardly survives being fixed on cards: ""I feel like a bowl of salad."" ""That's funny, you don't look like a bowl of salad."" There are two other, slighter skits and some appended ""show-stoppers"" (knock-knocks, daffynitions) to ""warm up the audience or leave them laughing!"" Maybe, if the audience consists of parents and their offspring have created the show from scratch--but the charm is considerably diminished when canned.