I am a big fan of America's Got Talent. I like to watch all of the amateur performers trying to make it big. Some of them are really good and others not so much. I think a lot of them could do a lot better if they just had some audition coaching like what is advertised at the preceding link. Sometimes the performers will do really well and then their next performance falls flat.
That is a sign that they are not getting good coaching and evaluation before their performances. That is really too bad because one bad performance after several good ones can knock them out of the competition. Many of these people will only get one chance in their lifetime and they need to make sure that they make the best of it.