There is a whole series of these commericals. Talking heads in front of a neutral background speaking over music which doesn't even sound like anything from the show.
I suspect it's an attempt to sell a piece of musical theatre to people who don't particularly like musical theatre. Say what you will about these commercials, they remove the "corn" factor from the equation.
TT
"Me flunk English? That's unpossible!" - Ralph Wiggum