Involving people with dementia in group exercise activities often presents a challenge. The effects of a recorded instrumental musical accompaniment was evaluated on participation in a series of 14 exercise activities with a group of nursing home residents with dementia. All exercise sessions, specifically designed by physical therapists for older adults, were lead by an activity aide and consisted of a series of seated exercises. Direct observations of resident behavior were conducted over a 25-week period in a reversal experimental design. Results showed increased levels of participation during the experimental condition observations where rhythmic music accompanied the exercise activities. The music intervention was most successful on those generally most willing to participate in social activities.