Music therapy, an intersection of art and science, is gaining recognition as a complementary approach in cancer care. This review systematically explores its mechanisms, applications, and effectiveness, with a focus on its impact on the tumor microenvironment (TME), particularly immune signaling and inflammation at single-cell resolution. Evidence shows that music therapy alleviates psychological symptoms-such as anxiety and depression-and physical discomforts including pain, fatigue, and nausea. Beyond symptomatic relief, it also modulates immune responses, especially in immune cell populations that influence tumor-associated inflammation and cancer progression. Advances in single-cell technologies may begin to explain how music therapy modulates immune signaling pathways within the TME, potentially enhancing treatment efficacy.Despite its non-invasive, cost-effective nature and high patient acceptability, music therapy remains underutilized in oncology. Further large-scale studies are needed to elucidate its molecular mechanisms, refine intervention models, and validate its role in immune modulation. As research advances, music therapy holds promise as a valuable component of integrative oncology, supporting patient recovery and immune homeostasis.