In my opinion, Jon's downfall occurred between 1998 and 2000.

During the Destination Anywhere Tour Jon was still easily hitting the high notes he had once hit through out the These Days Tour. For example, at the end of every performance of Destination Anywhere (the song) jon would hit these amazingly high and full notes, which the Jon we know today would only dream of hitting.

Even during the 1998 Florida show (w/ Bon Jovi) Jon pretty much sounded the same as he did during the mid 90s. Although, when looking at 2000 and onwards the change seen is devastating. Somehow, between 1998 and 2000, Jon's voice gained this annoyingly nasal tone, which has only gotten worse as time has dragged on.

So, to me, it is not age, because Jon in 2000 was 38 and such a drastic change (due to age) would not happen between the ages of 36 and 38.

I believe (just my theory), that his smoking habit in addition to a change of vocal teacher (or rather lack of) brought him to his downfall. Jon Bon Jovi up until 1998 could still sing Always and These Days perfectly. The Jon of 2 years later (and onward) could not.

But WHY?

What happened in those 2 years? That I'd like to know.

Oh and for the record (in regards to Axl Rose), Jon would be glad to hit these notes today: