Seventy-six in-patients who had the residual subtype of schizophrenia were randomly assigned to a treatment group or a control group. Both groups received standard medication as prescribed by their treating physicians, but the treatment group also received a one-month course of music therapy that included both passive listening to music and active participation in the singing of popular songs with other patients. Outcome was evaluated by four nurses using Chinese versions of the Scale for Assessment of Negative Symptoms and the in-patient version of the World Health Organization's Disability Assessment Scale. Music therapy significantly diminished patients' negative symptoms, increased their ability to converse with others, reduced their social isolation, and increased their level of interest in external events. As music therapy has no side-effects and is relatively inexpensive, it merits further evaluation and wider application.