Group Drum-Based Music Therapy Intervention for Parkinson's Disease/Huntington's Disease

Participants in this study (18-89 years) with Parkinson's disease or Huntington's disease receive drum classes twice a week for 12 weeks (24 lessons). All participants also participate in study visits for assessments before the beginning of the study, at the 6 week mark, at the 12 week mark and at the 18 week mark so that the investigators can assess the short and long term effects of drum classes on hand dexterity, upper extremity function and well-being.

Inclusion Criteria: Patients with Parkinson's Disease (PD) and Huntington's Disease (HD) * Ability to give written consent * Age 18-90 * Clinical diagnosis of probable of clinically established Parkinson disease; or Huntington disease confirmed by genetic testing (greater than or equal to 36 CAG repeats) * Ability to move hands, wrists and arms safely for instrument play * Presence of study partner who is available for all drum lessons and study assessments Study Partners: * Ability to give written consent * Ability to give written consent * Age 18-90 * Ability to move hands, wrists and arms safely for instrument play Exclusion Criteria: * PD: Hoehn \& Yahr Stage 5 disease; Schwab \& England score 40% or lower * HD: Total Functional Capacity scores between 5 and 13 inclusive * Co-morbid diagnosis (broken bones, sprains, severe arthritis, conditions involving paresis) in the judgement of the patient's treating physician that may preclude participant's full ability to participate in the intervention group. * MoCA scores \