Music therapy has a wide range of uses in health care practice. The aim of this study was to investigate the effects of intraoperative music played during spinal anesthesia operation on the patients' intraoperative vital signs, postoperative pain, and anxiety. Material and Methods: A randomized controlled clinical trial was conducted in the knee replacement surgery with spinal anesthesia. 90 patients were recruited and randomly assigned to either music therapy group (n:30), non-sedated group (n:30) and sedated (n:30) group respectively. The music therapy group received standard care and music intervention (self-chosen) during the operation, the non-sedated group received only standard care and the sedation was performed to the sedated group. Measures include pain, anxiety, vital signs (systolic and diastolic blood pressure, heart rate and respiratory rate). Results: Intraoperative respiratory rates of the music therapy group were significantly different in the three groups, but there was no difference between the groups in terms of vital signs. No complication was observed in the music therapy group during the operation, but complications were observed in the non-sedated and sedated groups. Similar postoperative pain was observed between the groups. However, the postoperative pain score was lower in the sedated group. The interventions in the music therapy group significantly altered the postoperative anxiety levels. Conclusion: Music therapy performed during spinal anesthesia was found to be a cost-effective method that was as competent as sedation on vital signs, pain, and anxiety. Moreover, it also increased patient satisfaction.