Casey Kasem Doing Top Ten List on David Letterman [VIDEO]

Legendary Radio DJ Casey Kasem  passed away at the age of 82 yesterday after a long battle with Parkinson's disease.

Kasem was best known as the host of radio countdown show "America's Top 40" and was also the voice of "Shaggy" from the cartoon Scooby Doo

At the end of every radio show Kasem would close with "Keep your feet on the ground, and keep reaching for the stars"

Here's a hysterical clip of Casey Kasem making an appearance on Late Show with David Letterman back in 1993