In reply to Sjl.

I don't think it was nerves. She is a seasoned performer. I think her girdle was on too tight. Her waist line was much fuller on the Caution tour . Here, because it was an award show I bet her team decided to make her girdle super tight since it is televised and the problem with that is it restricts her use of her diaphragm muscle to sing with. Hence, why she was able to hit her legendary whistle notes with ease but struggled sometimes with the lower notes.