"Letter S Song" is a Sesame Street song performed by Snuffy and Big Bird, under the vaudeville names of "Mr. Snuffleupagus and Mr. Bird." The scene spoofs the vaudeville standard "Mister Gallagher and Mister Shean." In the routine, Mr. Bird asks Mr. Snuffleupagus musical questions about S words. In between verses, they recite jokes that stress the S sound in the punchline. The act comes to an end when they're both dragged off by stage hooks.