I'm My Own Grandpa

""I'm My Own Grandpa""
novelty song
Released	1947 when performed by Lonzo and Oscar
Writer(s)	Dwight Latham and Moe Jaffe
Language	English

"I'm My Own Grandpa" (sometimes rendered as "I'm My Own Grandpaw") is a novelty song written by Dwight Latham and Moe Jaffe, performed by Lonzo and Oscar in 1947, about a man who, through an unlikely (but legal) combination of marriages, becomes stepfather to his own stepmother — that is, tacitly dropping the "step-" modifiers, he becomes his own grandfather.

In the 1930s, Latham had a group, the Jesters, on network radio; their specialties were bits of spoken humor and novelty songs. While reading a book of Mark Twain anecdotes, he once found a paragraph in which Twain proved it would be possible for a man to become his own grandfather. In 1947, Latham and Jaffe expanded the idea into a song, which became a hit for Lonzo and Oscar.

Family tree showing how
the narrator of the song
is his own grandfather.

In the song, the narrator marries a widow with an adult daughter. Subsequently, his father marries the widow's daughter. This creates a comic tangle of relationships by a mixture of blood and marriage; for example, the narrator's father is now also his stepson-in-law. The situation is complicated further when both couples have children.

Although the song continues to mention that both the narrator's wife and stepdaughter had children by the narrator and his father, respectively, the narrator actually becomes "his own grandpa" once his father marries the woman's daughter.

The song continues with

According to a 2007 article, the song was inspired by an anecdote that has been published periodically by newspapers for well over 150 years. The earliest citation was from the Republican Chronicle of Ithaca, New York on April 24, 1822 and that was copied from the London Literary Gazette:

A proof that a man may be his own Grandfather.—There was a widow and her daughter-in-law, and a man and his son. The widow married the son, and the daughter the old man; the widow was, therefore, mother to her husband's father, consequently grandmother to her own husband. They had a son, to whom she was great-grandmother; now, as the son of a great-grandmother must be either a grandfather or great-uncle, this boy was therefore his own grandfather. N. B. This was actually the case with a boy at a school in Norwich.

An 1884 book, The World of Wonders, attributed the original "remarkable genealogical curiosity" to Hood's Magazine.

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Wikipedia