Hallelujah Sequence

Generally, a scene in a movie where there's a super sad song playing because the main character is alone and is about to lose all the good things in their life.

Term originally coined by Schaffrillas Productions in his video: "Why Shrek the Third is a Cinematic Disaster".

Jacob: "Hey, didja see that movie I sent you the other day?"
Paul: "Yeah, there was a really sad Hallelujah Sequence in that one. It made me cry for a bit."