Jonathan Winters On the Ledge is a television special Jonathan made in 1987. Completely improvised, this special co-stars Robin Williams, Phyllis Diller, Milton Berle, Martin Mull, and Michael Richards - all in mostly unfunny skits.
The premise is: Jonathan sits up on the ledge of 38-story apartment building and taunts the members of a parade going on below. Then we jump to Jonathan's "father" (Berle sitting in front of a TV, smoking a cigar) complaining about how much he disapproves of Jonathan's humor. We then see various flashbacks and skits which all feature Jonathan in some character or another.
I am a huge fan of Jonathan Winters, but this special just isn't very funny. I don't blame J.W. for this because he is really a very talented man, and you can see him trying here. I do, however, blame the director (Peter Ferrara) for throwing a bunch of comedians and actors (some of who are not AT ALL talented in the art of improvisation) into empty, unrelated, mish-mashed vignettes and presenting it as entertainment.
Winters' brand of extemporaneous humor is very delicate; if it's not presented properly, the viewer loses appreciation for the jokes. And if Winters doesn't have someone (or something) good to play off of, the result isn't always funny. I get the impression from watching this special that the director just threw Jonathan onto a few already-made sets, added some big-named stars, pointed the cameras, and strung together whatever they came up with.