I remember seeing this performance when it first aired and was blown away by how good Scott sounded that night. I think this performance was an exception, not a typical example of his abilities at that point in time. But what an exception!!
I'm willing to bet this performance, along with pretty much any other "made for TV" performance is doctored/rerecorded in the studio after the live shows.
You can see him moving the mic around, but for some reason his voice doesn't get softer then louder then softer again.....
Still a great performance. Scott really can put on a show, acting a fool singing flailing all errywhere, or just standing in front of the mic focusing on the vocals.