Mark Van Tongeren explains overtone singing, and gives a demonstration on the Shanghai metro – because why not? Mark Van Tongeren is an ethnomusicologist and singer who lives in Taiwan. He has extensively studied overtone singing techniques around the world and is the author of Overtone Singing which covers the scientific and spiritual aspects of overtone singing traditions around the world. For more information on Mark and his work, check out his website at http://www.fusica.nl Interview by Pete Jackson Filming & editing by Peter Dixon