I arrived early, I usually do, and sat in the lobby of the theater listening to the ticket seller and house manager talking about voice problems. They trashed surgery, citing Julie Andrews and Elton John as victims.
I explained that in the middle of my voice is a dead note. I can sing above it and below it, but not across it.
The house manager explained the Stemple method to me. With your lips almost closed, almost a hum, you sing one note very softly with a bit of buzz on your lips, and hold it as long as you can. Then you do it again. In a few weeks you will be good as new. I'll have to try it.