This research was conducted to investigate the influence of music therapy on the behavior of rats at different stages of development. The procedures were performed when animals were approximately 1 month of age, and repeated once they completed 2, 3, and 4 months. Mozart’s Sonata for Two Pianos was played at a sound intensity of 65 dB for 4 hours per day, 2 hours in the morning and 2 hours in the afternoon (12 hours, for 4 days) when the animals reached each age. In the Open Field test, the locomotion in rats with 4 months old was significantly less than in other ages. Female rats 1, 2, and 3 months old, which were exposed to music, increased the percentage of open arms time in the Elevated Plus Maze test while male rats 1 month old reduced this parameter. The statistical differences were observed in the Forced Swimming test only when both genders were 1 month old. In the Inhibitory Avoidance test, an improvement in age-dependent memory was observed. The music therapy based on Mozart’s Sonata for Two Pianos positively interfered with the behavior of rats at different developmental stages. This result corroborates the clinical practice of palliative care, in which music therapy is generally used to improve patients’ quality of life with anxiety and depression.