A lullaby is a soothing and relaxing piece of music, usually played or sung to children. The purposes of lullabies vary. In some societies they are used to pass down cultural knowledge or tradition. In addition, lullabies are often used for the developing of communication skills, indication of emotional intent, maintenance of infants' undivided attention, modulation of infants' arousal, and regulation of behavior. Perhaps one of the most important uses of lullabies is to help relax children and aid them to fall asleep. As a result, the music is often simple and repetitive.
Studies find that gentle music therapy not only slows down the heart rate of prematurely delivered infants but also helps them feed and sleep better. This helps them gain weight and speeds their recovery.
More recent research has shown that lullabies can have beneficial effects on physiological functioning and development in premature infants. The live element of a slow, repetitive entrained rhythm can regulate sucking behavior. Infants have a natural tendency to entrain to the sounds that surround them. Beat perception begins during fetal development in the womb and infants are born with an innate musical preference. Many lullabies, regardless of the meaning of their words, possess a peaceful hypnotic quality which are beneficial to babies.