(literally, theater) Regardless of what happens, whatever show has been planned still has to be staged for the waiting patrons.
(idiomatic) One must finish what one has started; things must continue no matter what.
Source: en.wiktionary.orgI believe the show must go on. Shahrukh Khan
I vowed that whenever my family needed me, I would give up everything to go to them, no matter what. The show must go on was meaningless to me. Kate Smith
Traditionally the show must go on which is a stupid thing to say, but that in a nutshell is what's going on. We have a new record out; if we won't tour, the new record dies. It's reality - it's what business is nowadays. You just need to tour to sell your albums. Kerry King
I'm not used to introspection. I've never lingered on my feelings. The show must go on. Brenda Lee
For me, the show must go on - it doesn't matter how ill you are, you get on and do it. Martine McCutcheon
He says the above hilarious quote, a malapropism of "The show must go on", and tells her that everything always goes wrong and she just has to deal with it. Source: Internet