The aim of the study is to investigate the improvement of upper extremity functions with piano training of adolescent cerebral palsy. Nine adolescent cerebral palsy patients admitted to the Pediatric Disability Clinic between 2018 and 2020 and 9 healthy adolescent volunteers as control group were included. Therapeutic Instrumental Music Performance method was applied 2 days a week, 3 months in 40-min sessions. Before/after intervention, MACS, Box Block Test, Nine-Hole Peg Test, Jamar hand dynamometer and key pressing force of fingers were evaluated with Cubase MIDI program. Five of our patients included in the study were spastic hemiplegic and 4 were spastic diplegic cerebral palsy. All measurements made after intervention were found to be statistically significant compared to the measurements made before piano training (p < 0.05). The fingers that improved the most in the key pressing force of the fingers were found as the right hand 4th, left hand the 4th and 5th fingers (p < 0.01). A significant strong negative relationship was detected between the Box Block Test and the Nine-Hole Peg Test (p < 0.001). With therapeutic instrumental music performance method, functional gains can be achieved in the grip strength, strengths of the fingers, gross and fine motor skills of adolescent cerebral palsy patients. Further studies are needed to establish a piano training protocol in neurological music therapy.