The purpose of this study was to use Rhythmic Auditory Stimulation (RAS) for children with spastic cerebral palsy (CP) in a clinical setting in order to determine its effectiveness in gait training for ambulation. RAS has been shown to improve gait performance in patients with significant gait deficits. All 25 participants (6 to 20 years old) had spastic CP and were ambulatory, but needed to stabilize and gain more coordinated movement. Participants were placed in three groups: the control group, the therapist-guided training (TGT) group, and the self-guided training (SGT) group. The TGT group showed a statistically significant difference in stride length, velocity, and symmetry. The analysis of the results in SGT group suggests that the self-guided training might not be as effective as therapist-guided depending on motivation level. The results of this study support three conclusions: (a) RAS does influence gait performance of people with CP; (b) individual characteristics, such as cognitive functioning, support of parents, and physical ability play an important role in designing a training application, the effectiveness of RAS, and expected benefits from the training; and (c) velocity and stride length can be improved by enhancing balance, trajectory, and kinematic stability without increasing cadence.