I'm currently in the pit playing 2nd bone for a local theatre production of Singin' In The Rain. It has surprised me somewhat with how much playing and how challenging of a show it is. But the incident in question happened not during the "mean looking" key of G-flat tenor clef "Moses Supposes", but (I think) a "Broadway Revival" sequence that has my part jumping to a fairly crazy bass line double that involves our favorite pitch range on trombone:


thru


Side note: I thought there was note icons for every basic position in the staff, but I don't see a note for first space, i.e., bass clef A?
Anyway, I don't remember doing this damage specifically before - maybe I have and didn't notice. Any advice for future prevention is very welcome.