Many of our Baby Sleep CD's contain 're-written for baby ears' classical music.  This is because classical music has sound patterns that are not dissimilar to the mother’s voice, which is why it our baby sleep CD's penetrates more easily than other forms of music through the wall of the uterus. The unborn baby forms a memory of the sound patterns that echo through the womb. Hearing the same baby sleep CD's after birth can have an immediate and calming effect on the baby.  Research shows that baby sleep CD's that contain classical music of a slow pace can promote better sleeping patterns and deeper sleep.