Funny thing about starting out in the wrong key... particularly if it's higher than the one that you normally sing in. If you're in a group, and you start too high, you push everyone else to the top (or beyond) of their range. I did that recently on an a capella song I do with my group and the guys figured I'd stop and start over. But, I kept plugging along, managing to hit the high notes, and everyone else was blue in the face, trying to hit theirs. I won't do THAT again...

But as is usually the case, I think we were the only ones who realized that we were singing at the very top of our ranges.
Jerry