Pretty much everyone who played Rutledge in "1776" during the original run had vocal problems and ultimately had to leave because of them.
I remember feeling terrible when I was playing the part years later, until I asked Mary Bracken Phillips, who had replaced Betty Buckley in the original Broadway show. She told me they ALL had trouble with it. Every single one.
The problem is that it's a one-act musical, and no matter how well or how much you warm up before the show begins, if you're playing Rutledge, you basically sit relatively quietly on stage with a line here, a line there, and a bit of singing (not much to speak of)... and then comes your big 11 o'clock moment, which consists of about a 6-minute-long rant, power-belt song, and vocal slave auction that stops the show. It's a "let it loose" mini-marathon, and you really have to shake the rafters with it to pull it off effectively.
...And then you walk off the stage and (basically) collapse when it's done.
It has to do with the show's construction more than anything, and no amount of vocal training or preparation is going to help you with that. You sit in silence for 90 minutes, and then bellow and moan for 6 minutes solid.
It's kinda like not talking for an hour and a half, and then singing Sweeney Todd's "Epiphany" full-out.
I worked very carefully with my own voice teacher (who was formerly with the New York City Opera), and he did his best, but said, basically, quit the show and your voice will get better. He helped as much as he could, but short of me doing "warm-ups" ON STAGE while the show was going on, he said he couldn't help.
I'm sure the specific difficulties of other roles mentioned have played into the problem, just as much as bad vocal technique.
"Jaws is the Citizen Kane of movies."
blocked: logan2, Diamonds3, Hamilton22