Philip Glass talks about his opera "Satyagraha," playing at the Metropolitan Opera in the first revival of Phelim McDermott and Julian Crouch’s innovative 2008 production. Based on the life of Gandhi, it explores his enduring philosophy of non-violent resistance. Satyagraha is the second part of Glass’s famous trilogy of operas about important historical figures, which also includes "Einstein on the Beach" (1976) and "Akhnaten" (1983).