The mistakes we make with language often have particular names for them, especially when those mistakes amuse others. A malapropism occurs when we unintentionally use the wrong word or phrase. If the wrong word sounds like the correct word, like "duck tape," it is called an eggcorn. If we persist in using the wrong word even after being corrected, that's termed a mumpsimus. When words, usually in a song, produce unintended meanings when translated into another language, that's called a soramimi. When we simply say the wrong word or name because our minds are focused elsewhere, it's usually just called a Freudian slip.
Then there is the mondegreen, which is like an eggcorn but is more specifically what happens when we mishear the words to a song, a poem or something like the Pledge of Allegiance or the Lord's Prayer. Children have a unique gift for coming up with amusing mondegreens, a staple of the Family Circus comic for decades, but adults often make the same kinds of errors, often when listening to popular songs where the lyrics are not clearly enunciated.
The word mondegreen was coined in the 1950s by Sylvia Wright in Harper's magazine. She recalled that as a little girl she misheard a line from the 17th century ballad The Bonnie Earl of Murray. She thought she heard, and thus repeated:
Ye Highlands and ye Lowlands,
Oh, where hae ye been?
They hae slain the Earl o' Murray,
And Lady Mondegreen.
The last line of the stanza actually reads "And laid him on the green."
Jim Bernhard, in his book Words Gone Wild, tells of a minister who found his five-year-old son burying a dead robin. Before placing the bird in the hole he had dug in the ground, the boy prayed, "Glory be unto the Father, and unto the Son, and into the hole he goes."
Gavin Edwards remembers that as a boy he thought the line "life is but a dream" in the song Row, Row Your Boat" was "life's a butter dream."
Some mondegreens have become almost legendary:
"Double, double, toilet trouble," from Macbeth.
"Scuse me while I kiss this guy," from Jimi Hendrix's Purple Haze. (Actual words: "kiss the sky.")
"Surely good Mrs. Murphy shall follow me all the days of my life," from the 23rd Psalm.
"Round John Virgin," from Silent Night.
"Glory, glory, Honolulu," from the Battle Hymn of the Republic.
"Bringing in the sheep" or "bringing in the cheese," from Bringing in the Sheaves.
Sometimes a mondegreen can actually replace the original line. This happened with The Twelve Days of Christmas, long a popular holiday song. The line "four colly birds" (meaning black birds) was sung so persistently as "four calling birds" that eventually publishers of the song just gave up and printed "four calling birds." It is said that both Jimi Hendrix and John Fogerty (whose line "There's a bad moon on the rise" from Bad Moon Rising was often heard as "There's a bathroom on the right") actually sang the misheard lyrics in later concerts.
The title of one of the most read novels of the 20th century, The Catcher in the Rye, stems from a mondegreen. The poet Robert Burns wrote "Gin a body meet a body/coming' through the rye," but it is commonly heard as "Gin a body catch a body/comin' through the rye."