Michael was having throat problems on the History tour, I can't remember what exactly, but he was having health related issues. That's why he sounded the way he did at the times he sung live.
He was in his vocal prime during History and he still is. Michael hits high, powerful notes all the time without it being rough. In "Speechless" he does, in "You Rock My World", in "Don't Walk Away", "The Lost Children", etc... And if we're going to talk about his vocals on "History", which are some of his best ever, he hits high, clear notes on "Childhood", "Earth Song", "Smile", etc... His voice has retained all of its quality and range. It's a style he impliments. But if you listen to these songs, when he wants to sing with intensity and aggression, that's when he puts that grit in his voice, when he want's to sing with a softer, more sensitive emotional touch, he sings smooth and clear. Believe me, he has phenomenal range and can sing in any style and register he wants and control it the way he wants. His staccatto vocals are something to be admired, by the way. People don't understand how difficult it is to sing like that. Cutting off the end of each note and then moving in to the next one, its almost impossible and most singers wouldn't be able to even concieve of singing in that style, let alone actually do it.
