Hush Little Baby...

Hush, little baby, don't say a word,
Mama's going to buy you a mockingbird.

And if that mockingbird won't sing,
Mama's going to buy you a diamond ring.

And if that diamond ring turns brass,
Mama's going to buy you a looking glass.

And if that looking glass gets broke,
Mama's going to buy you a billy goat.

And if that billy goat won't pull,
Mama's going to buy you a cart and bull.

And if that cart and bull turn over,
Mama's going to buy you a dog named Rover.

And if that dog named Rover won't bark,
Mama's going to buy you a horse and cart.

And if that horse and cart fall down,
You'll still be the sweetest little baby in town.

(From Wikipedia)
Hush, Little Baby is a traditional lullaby. It is thought to be American (mockingbirds are from the American continent), but the author and date of origin are unknown. The lyrics promise all kinds of rewards to the child if he or she is quiet.

The structure is simple enough for parents to ad-lib further verses as required. This song has had the unusual distinction of two separate manifestations as a popular song, first as the song "Bo Diddley" by the singer of that name, and then as "Mockingbird", a well-selling song by the brother-and-sister team, Inez and Charlie Foxx in 1963, and then, for then husband and wife, James Taylor and Carly Simon in 1974, singing the Foxx arrangement. Toby Keith and his teenage daughter Krystal covered the song in 2004.

Singer James Hetfield recites a variaton of "Hush Little Baby" in the 1991 Metallica song "Enter Sandman". In 2005, rapper Eminem adapted "Hush Little Baby" into a song called "Mockingbird" for his daughter.