A Night at the Opera

Not Marx brothers, but Death in Venice by Benjamin Britten. Not exactly a toe tapping, sing-a-long opera but a grand opus. Brittan is not noted for his lavish musical accompaniment and melodies were few and far between, so a very difficult opera to sing.
The Principle singer was on stage for the whole 2 hours and sang, by himself, almost every single minute of it.
I really enjoyed it.