Look, it happens. We all have to face it at some point. We get old and we just can't do the same things we did in our youth. Take professional athletes, for instance. It's a big deal when an NFL player is able to keep going into his late thirties, just by the very nature of the game.
Metal is about the same, and it's not helping anyone how demanding the genre has become. It's easy enough for bands like Slayer to keep going, while admittedly toning down their movement onstage. These death-metal guys, though? Not a chance.
Especially the vocalists. It's sad to say, but at a certain point the throat can no longer take that kind of abuse. Then what do you do? Some retire, some try to go on with adjustments, and some just suck it up onstage every night. Here we'll see examples of all three as we examine what happens when the scream goes.