Answer: diewalkure

AnswerCrossword Clue
DIEWALKURE1870 opera famously excerpted in "Apocalypse Now"
DIEWALKURELincoln Center production.
DIEWALKUREGerhilde, Ortlinde, et al.
DIEWALKURESecond of a musical tetralogy
DIEWALKUREOpera by Wagner: 1856