I think posi-thought, affirmational thinking and positive music do work, and there is evidence supporting this. Trainers and athletes have been using mental training for years. In fact, the Pittsburg Steelers trained just as hard mentally for the Superbowl as they did physically - with phenomenal results. 

Scientifically, we have proof that different thoughts have different waves and forms. By putting a positive picture in our mind, our brains focus on the possible paths to achieve the desired result. The same would and does happen with negative thought, even if we don't intend it. The brain doesn't have an image to associate with the words don't or can't so if you're telling yourself to not do something your brain is seeing only the picture of whatever you are denying. (This is why it's so much fun to tease someone when they need to go to the bathroom.)

I also need to point out that my participation in the same mental training as Santonio Holmes will not result in me scoring winning touchdowns. None of the positive thought, affirmational thinking or positive music works without realistic planning and goal setting. They're all pieces of the same puzzle.