It's the pivotal moment in "Beetlejuice Beetlejuice."


The mischievous Beetlejuice has Lydia exactly where he wants her—dressed in a red gown and standing beside him at the altar, with a priest officiating. She has agreed to marry him to save her daughter's life. A towering cake, adorned with slimy green icing and figures of Lydia and Beetlejuice, is rolled out.


And then … the cake begins to ooze.


A male voice croons, “MacArthur’s Park is melting in the dark / All the sweet, green icing flowing down,” as the possessed wedding party—including Lydia’s stepmother, Delia (Catherine O’Hara)—dance around the cake, lip-syncing the verses.


This surreal sequence, largely improvised according to director Tim Burton, sets the stage for a chaotic wedding. The choice of song is as unconventional as the use of Harry Belafonte’s rendition of the Jamaican folk song “Day-O” in the dinner-table possession scene of Burton’s original 1988 film.


So, what is this song? Why did Burton select it as the new “Day-O”? What do the lyrics signify? Here’s a guide to unraveling the mystery.