Purpose <p>Music therapy is a beneficial supportive intervention in oncology. However, many patients undergoing cancer treatment face treatment-related physical impairments that limit participation in in-person sessions. This study explores the implementation of a video-based group music therapy intervention for patients undergoing tumour therapy.</p> Methods <p>A mixed-methods, single-arm study was conducted with 40 adult cancer patients. The intervention consisted of eight 90-min video-based group music therapy sessions. Standardized questionnaires and open-ended questions were used pre- and post-intervention. Therapists provided structured feedback after each session. Evaluation was guided by the RE-AIM framework (Reach, Effectiveness, Adoption, Implementation, Maintenance).</p> Results <p>Recruitment was efficient, with 40 of 44 screened patients enrolled. Attendance (90.1%) and completion (87.5%) rates were high. Participants rated the intervention as highly helpful (<i>M</i> = 4.77, SD = 0.49), with significant reductions in depression and anxiety (<i>p</i> &lt; 0.001). In their feedback, patients frequently reported shared musical experiences and a sense of emotional closeness as particularly meaningful aspects of the sessions. Therapists observed strong group cohesion despite initial technical challenges. Follow-up data indicated continued use of music in daily life, suggesting lasting impact.</p> Conclusion <p>Video-based group music therapy is a feasible and well-accepted intervention for patients undergoing cancer treatment. It addresses access barriers due to treatment-related physical impairments and supports continuity of care. The intervention showed promising results across RE-AIM dimensions, including symptom relief and integration into everyday life. Further studies should assess efficacy and explore adaptations for specific patient subgroups.</p> Trial registration <p>German Clinical Trials Register (DRKS00032339) (registered August 3, 2023).</p>