Back in 1989 Jim Henson and Frank OZ gave an in depth talk to The Puppeteers of America discussing their collaboration on The Muppets, Sesame Street, and other projects like The Dark Crystal and Little Shop of Horrors. To the delight of everyone, they also performed on stage as some of their more notable characters: Kermit, Rowlf the dog, Fozzie, Cookie Monster and Animal (basically, it was a wet dream for any puppet/muppet fanatic).
In 1993 Frank Oz taped an introduction to the captured lecture/performance making the whole hour-and-a-half long video feel a bit bittersweet since it was only three years after Henson's death from complications from Pneumonia (the talk itself was only ten months before his passing).
While watching the evening unfold on stage, you can't help but wonder what Henson might have continued to achieve had he not been taken from us before we were ready (I think we would have had that Fraggle Rock movie by now).
But at least we'll always have The Muppets Take Manhattan...