illustration from The April Baby’s Book of Tunes, by Kate Greenaway

A lullaby is a song designed to soothe young children to sleep, the best-known of which is probably “Hush-a-bye, baby, on the tree topPerhaps the best-known English lullaby, the earliest known version of which was published in about 1765.“; lullabies are also known as cradle songs.[1]

There are also instrumental lullabies, such as Chopin’s Berceuse.[2]