The Cradle Song is a reminiscence of Maria's youth in Carabanchel, a town in which her father was convent doctor and where her sister took the veil, the Sister Joanna of the Cross of the play. [Martinez] has paused to probe some universal passion or emotion... in The Cradle Song, to echo the cry of the eternal mother instinct while has been stifled and denied.... The Cradle Song has been translated into many languages, and has been played and imitated widely throughout the civilized world.