"So Long, Farewell" was a song from the Earth musical and movie The Sound of Music.
When Maldis was taunting John Crichton, he said, "Have you forgotten? Fear makes me stronger. Fear and the terror of helplessness. These are a few of my favorite things." Crichton was unimpressed, and he replied, "Oh, could you do that farewell good-bye song the kids sing? It's one of my favorites." ("Picture If You Will")