I heard this years ago on the local NPR station - KUT. If I remember correctly it began as I pulled into the parking lot at Barnes & Noble and I sat there listening to it all the way through, much to the bemusement of the people in the cars around me.
Anna Russell dissects a fictitious opera based on Shakespeare's Hamlet. Her humor stands the test of time. So, if you have about 30 minutes to spend on mindless comedic entertainment, please feel free to give this a listen.