People who THINK they're great singers (but they're not good at all).
We used to see them on "American Idol." Simon would mercilessly bash them. Now most people would decide that maybe singing is not for them. However, this special breed of person thinks that the pro's just got it wrong.
You may have a friend like this. I know, I do. She believes that she would be a huge star if only given the chance. So what does she do? Any chance she can sing, she does. In the car, at a store, in a restaurant, at church, etc. She's always the loudest and the most off-key.
Here's some people that fit in this category.