The overall objective of this study is to observe the effect of group Vocal performance training and performance experience on patients' reported symptoms and quality of life. The effectiveness of PD medications varies significantly in different patients depending on their symptoms. By using music-based interventions to improve symptoms that may be inadequately treated by medications, the investigators hope to improve quality of life in PD patients. "Parkinsonics: A controlled study of group singing for quality of life and voice outcomes in Parkinson disease" (PD) is a controlled crossover behavioral intervention study of once weekly choral classes for patients with idiopathic PD (progressing toward a group performance) and once weekly discussion/support group meetings.