Mairzy Doats was a popular novelty song in the ‘40s. It made the pop charts several times, with a version by the Merry Macs reaching No. 1 in March 1944. In addition to its success on the home front, it was a hit with servicemen overseas, who allegedly used its nonsensical lyrics as passwords.
At first glance the song’s refrain, as written on sheet music, seems meaningless:
Mairzy doats and dozy doats and liddle lamzy divey. A kiddley divey too, wouldn’t you?
However, the lyrics of the bridge provide a clue:
If the words sound queer and funny to your ear, a little bit jumbled and jivey,
Sing ” Mares eat oats and does eat oats and little lambs eat ivy.”
With this aid, the refrain is quite easily comprehended, and the ear will detect the hidden message of the final line: “A kid’ll eat ivy too, wouldn’t you?”