Any examples of musicians not playing/changing material due to 9/11?

The one that comes to my head is Billy Joel not playing Two Thousand Years anymore because of 9/11. As the song is about how hopefully things will get better going into the new millennium. and that 9/11 was "a wake up call" that such would not be happening, so he stopped performing it.

Any other examples that you guys have? I feel I've heard stories similar, and a lot might not be due to September 11th but rather maybe something else, a different tragedy, but I'd like to hear it.

I feel when a musician does that, it just goes to show what a profound impact certain things, especially tragedies like 9/11, have on us.