Upon admission, all infants in the NICU are placed on monitors that continuously track their heart rate, respiratory rate, and oxygen saturation. During our study, data will be collected from the monitors already in use. Total time of observation will be approximately 3 hours. In addition, a monitoring device called an Actiwatch will also be used. This device looks similar to a traditional wristwatch and will be loosely strapped to the ankle or wrist of each infant using a foam and velcro strap. This device continuously monitors the baby's movements allowing us to determine if there is a change in the baby's activity level while the music is being played. It will record the baby's activity prior to the start of the music and will continue until 30 minutes after the music has stopped.