Wow, you really mean it, leeneia! I just thought you were teasing.

Warming up is more than just tuning up, true enough. The same way that when athletes warm up it's more than just tying their shoelaces.

I suspect that you are very much in a minority here leeneia, and that most people in an audience actually welcome the cacophony at the start of a concert, and find it helps them to warm up and get ready for the music.