In response to the tendency for music to be under-represented in the discourse of medical humanities, we framed the question "how can music heal?" We answered it by exploring the lived experiences of musicians with lay or professional interests in health. Two medical students and a medically qualified educationalist, all musicians, conducted a co-operative inquiry with a professional musician interested in health. All researchers and six respondents kept audio or written diaries. Three respondents were interviewed in depth. A medical school head (and experienced musician) critiqued the phenomenological analysis of respondents' accounts of music, health, and its relationship with undergraduate medical education. Respondents experienced music as promoting health, even in seriously diseased people. Music affected people's identity and emotions. Through the medium of structure and harmony, it provided a means of self-expression that adapted to whatever condition people were in. Music was a communication medium, which could make people feel less isolated. Immersion in music could change negative states of mind to more positive ones. A transport metaphor was commonly used; music "taking people to better places". Exercising control by becoming physically involved in music enhanced diseased people's self-esteem. Music was able to bring the spiritual, mental, and physical elements of their lives into balance, to the benefit of their wellbeing. Music could help medical students appreciate holistically that the state of health of people who are either well or diseased can be enhanced by a "non-technical" intervention.