Marge vs. The Monorail is one of The Simpsons' most beloved episodes, and for good reason - it's got a plethora of great jokes (Homer's insistence on speaking to Batman, the Leonard Nimoy cameo, "I call the big one 'Bitey'"), an unusually adventurous plotline (con man is planning to send a bunch of Springfieldians to their death on a busted monorail), and another one of the great vocal performances by Phil Hartman, particularly the Music Man-inspired number, The Monorail Song.
As you might also know if you're a huge Simpsons nerd (and maybe even if you're not), the episode was written by pre-talk show era Conan O'Brien. And wouldn't ya know it, Coco himself appeared at The Simpsons Take the Bowl - a night of live performances by Simpsons cast members and more - to perform the song himself, live, for the first time ever.
Here's the song as it originally appeared on The Simpsons years ago: