[Norm Lenhart]

Because he loves singing, but can’t hit the notes his old material requires. But he can still sing the ones they don’t.

[Moonman62]

Because he loves singing, but can’t hit the notes his old material requires. But he can still sing the ones they don’t.
...

Other bands can sometimes get away with hiring female backup singers to hit the high notes. That probably wouldn’t work for LZ.