This study investigated the relationship between changes in mood and behavior and the number and setting (individual or group) of music therapy sessions received by people who have had a stroke or traumatic brain injury (TBI). Ten individuals who had had a stroke or TBl and some degree of depression received varying numbers of music therapy sessions in addition to standard rehabilitation. Some received group music therapy only while others were seen in both group and individual music therapy sessions. Evaluation included pre– and post–treatment assessments of participants' self–rating of mood, family ratings of mood and social interaction, and therapist ratings of mood and participation in therapy. The number of music therapy sessions seemed to influence several behavioral measures, with group sessions appearing to affect social interaction and individual sessions marginally affecting motivation for treatment. The number of group sessions was also related to family members' assessment of improvement in patients' moods in the previous 24 hours. Implications of this exploratory study for the delivery of music therapy services are discussed.