Bands That Replaced Irreplaceable Members (And Those That Shouldn't Have)

Cable television is confounding, for sure, and the inevitable question often arises: "All these channels and nothing to watch? What the ______?" Recently, I was having one of these moments until I stumbled across an interview/live performance show on the Audience Network called Guitar Center Sessions. This one caught my eye because it featured Alice in Chains. I got curious. Who is this new singer? How could they try to keep it going without Layne Staley?

Of course, this only brought up more thinking, which is never encouraged by any discernible taste-making entity, but darn it, thinking is so fun and on that particular afternoon, I wondered, what other bands have replaced seemingly irreplaceable members and either failed miserably or been successful? Obviously, it is way more fun to write about the bands who have failed miserably, but I also have to be fair and give credit where credit is due.