Singing for a Treatment (IMAGE) University of Missouri-Columbia Caption Jessica Colwell, a student in the School of Health Professions, prepares to sing for Radhakrishnan as he studies the differences between vibrato, an involuntary pitch fluctuation in classical singing, and Taan, a voluntary pitch fluctuation in Hindustani singing. Credit Christian Basi/University of Missouri Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.