There's the "Merry Minuet." Lehrer also wrote "So Long Mom, I'm Off To Drop The Bomb." I've always liked Silverstein's "Slithery Dee," too. There's that poem/song that starts "Hammacher Schlemmer is selling a shelter/Reminiscent of Kubla Khan's Xanadu dome...." Or "It Was A Helluva Funeral."