I can sing well when I'm fresh. It's the long days that get me. Three hours into a session my voice starts to fray, the top notes tighten, and I'm pushing through on fumes, terrified I'll do real damage. By the end I can barely talk, and there's another session tomorrow.
More people experience this than they realize.
You can perform well, but keeping your voice strong and healthy through long sessions trips you.
If this sounds familiar, the Library can help you find the bigger picture.