Music is one of humanity’s oldest medicines, reflected in cultures across the globe that have rich traditions in using sound and rhythm to ease suffering, promote healing, and calm the mind. Neuroscientist, author, and musician Daniel J. Levitin explores the critical role music has played in human biology; why he finds it one of the most potent therapies today; and how it can contribute to the treatment of ailments from neurodegenerative diseases to cognitive injury, depression, and pain.