This course will explore the potential of the human voice as a flexible instrument in historical, cultural, musical, and physiological terms. The once-celebrated castrato voice, described as “the sound of angels” and “curiously disembodied,” expressed the ambiguous gender of children's voices through a timbre incorporating both male and female qualities. In a technological attempt to recreate the voice of the most famous castrato for the 1994 film “Farinelli,” sound engineers blended the voice of a coloratura and a countertenor to approximate its unusual beauty. As a performance practice, the Onnagata of the Kabuki tradition also reveal shifting cultural norms around gender and identity, while today the disembodied voice takes on a new orientation through computers and animation. We will study how the voice can be trained and modified, highlighting a number of case studies of vocal manipulation through history and across cultures. Through this study we can develop innovative ways to expand our understanding of the voice for performance and research.