Tell us about a classroom or ensemble fail you had - I'll start..
I was in my first year of teaching middle school choir. I had my freshly-minted MM in conducting, but never had an education class. So, classroom management was the Wild West for me! Anyway, there was a 7th grade boy who would not stop talking during rehearsal, so I threatened to lock him in the (dark and damp) janitor's closet if he spoke out of turn again. Sure enough, he did, and I followed through. I have to admit it was effective and he was an absolute angel for the rest of the year, but I'm pretty sure I would be fired (or jailed?!) if I did that in the 21st century! 😅