Background: Patients with heart and lung disease participate in cardiopulmonary rehabilitation programs to improve or regain the stamina lost due to sedentary lifestyles and exacerbating events. Though beneficial, exercise can be unpleasant. Music, as a form of distraction, has been used to make the activity more enjoyable. Adherence to regular exercise is related to enjoyment. This study examined the effect of favorite music on the exercise experience of cardiopulmonary rehab patients. Methods: In a crossover trial, 45 patients from cardiopulmonary rehabilitation programs were randomized to a sequence of three music and three control sessions during exercise once per week over a period of six-weeks. The primary outcome measure was MET-minutes of exercise and secondary outcome was enjoyment measured by a visual analog scale. Percent target heart rate, rates of perceived exertion and perceived dyspnea, and steps per minute were also measured. General well-being was assessed prior to exercise sessions. Results: Mixed-effects model showed no statistical difference in MET-minutes for music and control sessions (p=0.199). Music had a significant positive effect on enjoyment of exercise (p <.0001) and percent target heart rate (p=0.02). Perceived exertion and dyspnea were not significantly different (p =0.08 and p=0.16 respectively) for music versus control sessions. There was no association between steps per minute of exercise and music tempi. Feelings of general well-being were positively associated with enjoyment. Conclusions: Listening to favorite music resulted in higher levels of exercise enjoyment and target heart rate but did not show significant difference in MET-minutes, perceived exertion or dyspnea.