Background: The introduction of music therapy in intensive care units (ICUs) has resulted in a notable transformation in the experience of family members, conferring substantial benefits for both patients and their loved ones. Patients have demonstrated improvements in their emotional well-being, quality of life, and a reduction in anxiety and stress levels. Furthermore, music therapy intervention has facilitated the development of nonverbal communication and emotional connections between patients and caregivers. This approach responds not only to clinical needs but also contributes to the humanisation of care, emphasising the importance of the emotional well-being of the patient's family and recognising their crucial role in supporting the patient's recovery process. Aim: The aim of this study is to explore family members' experiences of the humanisation of the adult ICU. Methods: The present study was conducted in accordance with a qualitative hermeneutic phenomenological methodology. Interventions were conducted with a music therapist, and 14 in-depth interviews were collected from relatives in the critical care unit of Mostoles University Hospital in Madrid, Spain. The qualitative analysis employed was that proposed by Braun and Clarke, with an inductive approach. This method resulted in the emergence of three themes from the interviews. Main results: The personal interviews yielded a thematic analysis that revealed three dominant themes. These themes encapsulate the experiences and emotions of the study participants after completing the music therapy sessions. Three main themes have been identified: (i) music therapy responding to family concerns, (ii) music therapy during interventions, and (iii) music therapy to humanise the intensive care unit. Discussion: This study highlights the crucial contribution of music therapy in the humanisation of ICUs by enhancing the experiences of patients, their families, and healthcare professionals. It has been demonstrated to reduce stress, anxiety, and pain while fostering emotional connections and improving communication. The application of music therapy has been demonstrated to reinforce the therapeutic relationships between patients and healthcare professionals, reduce the necessity for sedation, and enhance comfort during medical procedures. In alignment with the principles of humanistic care, it is conducive to the promotion of well-being, intimacy, and quality of life. Despite certain limitations, the integration of music therapy is vital for the creation of more compassionate and patient-centred environments. Conclusions: Music therapy in ICUs enhances family satisfaction by improving patients' emotional wellbeing. Relatives recognise music as a comforting influence, positively shaping the hospital environment. It fosters a conducive atmosphere for familial interaction and support. Post-session, family members report heightened calmness and optimism witnessing the emotional benefits of music for patients. Thus, music serves as a therapeutic conduit, impacting the emotional journey of patients and their families alike. Limitation: One of the limitations encountered during the course of the study pertained to the issue of interviewing family members. On occasion, these individuals found themselves unable, or unwilling, to separate themselves from their loved ones for extended periods of time. This factor consequently resulted in a limitation of both the attention available for interviews and the time at the researcher's disposal. (c) 2025 Australian College of Nursing Ltd. Published by Elsevier Ltd.