Illustrator Caldecott had no problem with nonsense

Explaining nursery rhymes is a fruitful source of hypotheses for scholarly commentators. Children probably find it easier than adults to accept the illogic of such jingles, even if their favorite word is "Why?" (To which the self-preserving adult should always reply: "Why not?")

Some artists are inspired by the imaginative non sequiturs of nursery literature. They don't see why a cow shouldn't jump over the moon. Or why four and 20 blackbirds baked in a pie shouldn't come out singing. Such "Why not?" artists take nonsense in their stride. Victorian English illustrator Randolph Caldecott was one of them. (His name is borrowed for the medal awarded to a children's book artist in America each year.)

Caldecott instilled his drawings with funniness and high jinks that still delight. He originated much of the surprise, sparkle, and page-turning incentive that children's illustrators still relish.

Starting in 1877, he illustrated a total of 16 "toy books." "Sing a Song for Sixpence" is his cover for one of them. The diminutive "king" of the rhyme (a child in fancy dress) is beating a hoop-sized sixpence with "1880" on it, the date of the first edition. His "queen" (a little girl in gown and crown) is spooning out honey for her bread. Some of the blackbirds perch on blossom branches worthy of a Japanese print, ready for their quaint story to be told.

What follows between the covers of this slender book is full of similarly engaging originality. As Elizabeth Billington has rightly observed, "[Caldecott] did not decorate the stories, he interpreted them." He added marvellous little extras in his pictures and even a subplot of his own, giving a novel twist to the bare bones of the words.

In this case, he even dared to change one of the words. The usual "of" in the first line has puzzlingly become "for." But this mystery is explained the moment one opens the book to the first picture. It shows an old woman, seated, offering a sixpence to a group of children - presumably in exchange for a song.