There's 2 performances here. The first was at the AMAs when Christina Aguilera did a phenomenal tribue to the late Whitney Houston. So great that it moved arch rival, "Pink" to tears. That IS something.
I saw this kind of reaction once before when Ann Wilson of Heart moved BOTH Robert Plant and Jimmy Page to tears with, "Stairway To Heaven" at the Kennedy center honors.
For aspiring lead vocalists. If you watch these two performances you can get a great idea of where you need to go to "move" people. Speaking of Pink up above, she has that level of talent too.
Here's Heart doing, "Stairway To Heaven"