This is based on a traditional American folk song sometimes known as "Hush Little Baby." The song is a lullaby, intended to soothe a young child to sleep with promises of expensive gifts. Northern Mockingbirds were often kept as pets in America, which explains the significance of the lyrics.
Bo Diddley used the traditional lyrics for his 1955 song "Bo Diddley," but his song had a completely different arrangement.
Inez and Charlie Foxx were brother and sister. In 1974, James Taylor and Carly Simon, who were married at the time, recorded their version, which was also a hit. Country singer Toby Keith recorded it with his teenage daughter Krystal in 2004, and that same year, Eminem made it into a song for his daughter Hailie. Eminem's song veers from the traditional lyrics as he details his struggles to raise his daughter and threatens to break the bird's neck if it doesn't sing.
Toby Keith did a duet of this song with his daughter, Krystal, for his 2004 Greatest Hits Volume 2 album.