This study investigated changes in physical condition (heart rate, respiratory rate, oxygen saturation, weight) of newborns when mothers’ recorded lullabies were played to a group of high-risk newborns, and changes in mothers' emotion while recording lullabies. The investigator recruited 78 newborns and 59 mothers from three IRB (Institutional Review Board)-approved hospitals. Experiments were conducted by dividing participants into three groups (singing group, lyrics group, and control group), and conducting an intervention of 20 minutes per day for two days among mothers and seven days among the group of high-risk newborns. Data from the 72 high-risk newborns and 59 mothers, excluding dropout participants, were subjected to statistical analysis. The results showed that mothers' singing intervention significantly influenced the heart rate of the high-risk newborns. There was no significant difference in the respiratory rate, oxygen saturation, and weight. In addition, the process of recording singing showed a significant influence on mothers' positive and negative emotional responses. Therefore, the results of this study confirmed that lullaby interventions influence the heart rate of high-risk newborns, and found that playing the mothers' lullaby to newborns with higher frequencies of exposure to music during pregnancy had a positive influence on heart rate. Furthermore, the process of recording singing was also found to have positive changes in mothers' emotional responses.