Good gravy! One of the greatest episodes of The Simpsons (the twelfth episode of season four, "Marge vs. The Monorail") was written by none other than Conan O'Brien during his time on the show's writing staff.
At The Hollywood Bowl this weekend, O'Brien performed "The Monorail Song" during The Simpsons Take The Bowl, a three-night extravaganza featuring songs from the greatest television comedy of all time. He also paid tribute to the late Phil Hartman, who voiced many characters on The Simpsons, including fast-talking monorail salesman Lyle Lanley.
The song also features Hank Azaria as both Apu and Chief Wiggum. Unfortunately, Dan Castellaneta did not appear at the end of the song to give Homer's famous line: "Mono....(annoyed grunt)!"
Here's audio of the original song from The Simpsons: