Jerry Nelson, the veteran Muppeteer who created Count von Count, and various other Sesame Street characters from Sherlock Hemlock to Mr. Snuffleupagus, passed away last week at the age of 78.
Which means we may never find out why he migrated Count von Count's accent over the years from Transylvania to the Catskills. As this ersatz interview with the BBC in 2009 shows. The Muppet performers apparently do sound check and everything in character.
Did you know Nelson and some friends put out a CD in late 2009? Folk & blues guitar & ukelele, which sure sounds like they had fun.