"Ding-Dong! The Witch Is Dead" is the centerpiece of several individual songs in an extended set-piece performed by the Munchkins, Glinda (Billie Burke) and Dorothy Gale (Judy Garland) in the 1939 film "The Wizard of Oz". Like several of the songs on the film's soundtrack, this one makes extensive use of rhyming wordplay, containing as many Hays Office-approved words rhyming with "witch" as the composers could think of: "itch", "which", "sitch"-uation, "rich", etc.

There was to have been a reprise of the song, beginning "Hail Hail! The Witch is Dead", sung by the leader of the Winkies (the witch's guards) after the Wicked Witch of the West had been melted and the spell over them was broken, and the lead Winkie had given Dorothy the witch's broomstick. It was to be continued by the townspeople of the Emerald City, who would sing it in a medley along with a reprise of "The Merry Old Land Of Oz". This song and its scenes were cut from the film, which instead jumps directly from the witch's castle (minus the singing Winkie) to the Wizard's throne room.

More Info: en.wikipedia.org