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 <17 Active psychosis or other condition affecting the participants' ability to safely cooperate with study procedures